Appropriate non-carbapenems are not inferior to carbapenems as initial empirical therapy for bacteremia caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae: a propensity score weighted multicenter cohort study.

The efficacy of empirical non-carbapenem antibiotics for extended-spectrum beta-lactamase-producing Enterobacteriaceae bacteremia (ESBL-B) is still inconclusive. We conducted a multicenter retrospective cohort study to evaluate the efficacy of empirical non-carbapenem antibiotics for treating ESBL-B. Electronic medical records of individuals who were diagnosed with ESBL-B were reviewed between January 2010 and December 2014 at four university hospitals in Korea. Patients were classified into non-carbapenem and carbapenem groups according to the empirical antibiotic regimen. Patients treated with appropriate empirical antibiotics and who subsequently received carbapenems as definitive therapy were included in the analysis. The inverse probability of treatment weights, a statistical method that adjusts baseline statistics by giving weights based on propensity score, was used. During the study period, 232 adequately treated patients with ESBL-B were included in the analysis: 49 patients in the non-carbapenem group and 183 in the carbapenem group. The baseline characteristics and severity of infection were similar after propensity score weighting. The 30-day mortality rates for the two groups were not statistically significantly different (non-carbapenems 6.3% and carbapenems 11.4%; P = 0.42). In a multivariate analysis, empirical treatment with non-carbapenem antibiotics was not associated with 30-day all-cause mortality (HR 1.02, 95% CI 0.99-1.06, P = 0.14). In a subgroup analysis, empirical treatment with piperacillin-tazobactam was also not associated with 30-day all-cause mortality (HR 1.21, 95% CI 0.37-4.00, P = 0.75). Appropriate non-carbapenems were not inferior to carbapenems as initial empirical therapy for ESBL-B.

Impact of appropriateness of empiric therapy on outcomes in community-onset bacteremia by extended-spectrum-ß-lactamase producing Escherichia coli and Klebisella pneumoniae definitively treated with carbapenems.

Despite a significant increase of bloodstream infection caused by extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae in the community-setting, information regarding clinical outcomes of inappropriate empiric therapy (IAT) in patients with those infections is limited. A multicenter-retrospective cohort study was conducted in four hospitals. A total of 249 adults were identified to have community-onset bacteremia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae, and definitively treated with carbapenems. According to the appropriateness of empiric therapy, individuals were divided into an appropriate empiric therapy (AT) group (n = 106) and IAT group (n = 143). Patients who received AT showed more severe underlying conditions including underlying solid cancer, healthcare-association and intensive care unit (ICU) care, compared to the IAT group. Primary bacteremia was more commonly found in the AT group than in the IAT group, while urinary tract infection predominated more frequently in the IAT group than in the AT group. Multivariate analysis using propensity score analysis indicated that inappropriateness of empiric therapy was not an independent risk factor for 30-day death. ICU care, respiratory tract infection and underlying liver, renal and connective tissue diseases were significantly associated with mortality. In patients with bloodstream infections caused by ESBL-producing E. coli and K. pneumoniae in the community-setting, delay in appropriate therapy was not associated with an increased rate of death if the patients were definitively treated with carbapenems.

Hepatitis B infection is associated with an increased incidence of thrombocytopenia in healthy adults without cirrhosis.

The association between HBV infection and incident thrombocytopenia among subjects without cirrhosis or splenomegaly is unknown. Therefore, we sought to elucidate the association between HBV infection and the development of thrombocytopenia in a large cohort of apparently healthy men and women. A cohort study was performed in 122 200 participants without liver cirrhosis or splenomegaly who underwent comprehensive health examinations and were followed until December 2014. HBV infection was defined by the presence of hepatitis B surface antigen (HBsAg) at baseline. Thrombocytopenia was defined as a platelet count <150 000/µL. Cox proportional hazard models were used to estimate adjusted hazard ratios with 95% confidence intervals (CIs) for incident thrombocytopenia. HBsAg was positive in 4857 of 122 200 subjects (4.0%) at baseline. During 883 983 person-years of follow-up, 2037 incident cases of thrombocytopenia were identified (incident rate 2.3 per 1000 person-years). HBsAg-positive subjects had a higher incidence of thrombocytopenia than did healthy controls (11.2 vs 1.9 per 1000 person-years, respectively). The multivariate-adjusted hazard ratio (95% CI) for incident thrombocytopenia comparing HBsAg-positive to HBsAg-negative subjects was 5.71 (5.10-6.38). Strong associations between HBsAg positivity and thrombocytopenia were consistently observed across prespecified subgroups. In this large cohort study of an apparently healthy population, HBsAg positivity was strongly and independently associated with incident thrombocytopenia, indicating that mechanisms of thrombocytopenia other than portal hypertension may exist in healthy HBV carriers.

Insulin resistance increases loss of antibody to hepatitis B surface antigen in nondiabetic healthy adults.

The aim of this study was to evaluate the impact of insulin resistance on the persistence of a protective level of anti-HBs (hepatitis B surface antigen) in a nondiabetic general population. A cohort study was designed comprising of 38 473 Korean men and women with anti-HBs at concentrations ≥10 mIU/mL, who underwent a health examination. Insulin resistance was assessed with a homoeostasis model assessment of insulin resistance (HOMA-IR). A decline in anti-HBs to <10 mIU/L during the follow-up was considered to be a loss of protective anti-HBs. Cox-proportional hazard models were used to estimate the adjusted hazard ratios and 95% confidence intervals for anti-HBs loss across quintiles of HOMA-IR and insulin. We identified 20 826 incidents of loss of anti-HBs antibody during 180 522 person-years of follow-up (incident rate 11.5 per 100 person-years). Increasing HOMA-IR was positively associated with incident loss of anti-HBs. The multivariable-adjusted hazard ratios (95% confidence intervals) for incident loss of anti-HBs comparing quintiles 2-5 vs quintile 1 of HOMA-IR were 1.09 (1.04-1.14), 1.14 (1.09-1.19), 1.14 (1.09-1.19) and 1.21 (1.16-1.27), respectively. These associations were stronger in younger individuals under the age of 35 than in people 35 years of age or older (P for interaction = 0.004). The association was also more evident in subjects with higher titres (≥100 mIU/mL) of anti-HBs than in those with low titres (P for interaction < 0.001). Insulin resistance was associated with an increased risk for loss of vaccine-acquired anti-HBs in a large sample of a nondiabetic, general population, indicating a possible role of insulin resistance in vaccine-induced immunity.

Impact of acute kidney injury on mortality and medical costs in patients with meticillin-resistant Staphylococcus aureus bacteraemia: a retrospective, multicentre observational study.

BACKGROUND: Despite the frequent occurrence of acute kidney injury (AKI) associated with meticillin-resistant Staphylococcus aureus (MRSA) infection during treatment, the adverse impact of renal injury on clinical and economic outcomes has not been evaluated. AIM: To study the clinical and economic burdens of MRSA bacteraemia and the impact of AKI occurring during treatment on outcomes. METHODS: Medical records of patients hospitalized for MRSA bacteraemia between March 2010 and February 2011 in eight hospitals in Korea were reviewed retrospectively to evaluate the risk factors for AKI and mortality. Direct medical costs per patient of MRSA bacteraemia during treatment were estimated from the medical resources consumed. FINDINGS: In all, 335 patients were identified to have MRSA bacteraemia. AKI occurred in 135 patients (40.3%) during first-line antibiotic therapy. Independent risk factors for AKI were male sex, underlying renal disease, intra-abdominal and central venous catheter infection, and increase in Pitt bacteraemia score. Seventy-seven (23.0%) patients died during the study period. Underlying solid tumour, high Pitt bacteraemia score, and occurrence of AKI were independent risk factors for mortality. The mean total medical cost per MRSA patient was estimated as South Korean Won 5,435,361 (US$4,906), and occurrence of AKI and ICU admission were identified as independent predictors of increased direct medical costs. Compared with patients who retained their baseline renal function, patients with AKI had a 45% increase in medical costs. CONCLUSIONS: Patients who developed AKI showed significantly higher mortality rate and greater direct medical costs compared with patients who retained baseline renal function.

Impact of a computerized alert system for bacteremia notification on the appropriate antibiotic treatment of Staphylococcus aureus bloodstream infections.

A computerized alert system (CAS) has been introduced to notify bacteremia in real time. We evaluated the impact of the CAS on the administration of appropriate antibiotics in patients with Staphylococcus aureus bloodstream infections (BSIs). We retrospectively reviewed the medical records of patients with S. aureus BSI for each 1-year control and intervention periods, before and after the implementation of the CAS. The proportions of appropriate antibiotic treatment were compared between the control and intervention periods. The 30-day mortality of S. aureus bacteremia was also assessed in the study population. A total of 313 patients were included in the study. Appropriate antibiotics were initiated 7 h earlier in the intervention period (mean time, 13.5 h vs. 20.0 h; p = 0.136). The administration of appropriate antibiotics within the 24 h after blood acquisition was similar between the two periods, but this significantly increased from 3.3% in the control period to 10.6% in the intervention during the 24-36 h interval (p = 0.012). In the subgroup analysis, similar trends were observed in patients with methicillin-resistant isolates (6.7% vs. 18.2%; p = 0.032) and hospital-onset infection (3.5% vs. 17.1 %; p = 0.004). The independent risk factors for 30-day mortality of S. aureus bacteremia were age, a high Pitt bacteremia score, an increased Charlson's weighted index of comorbidity, and hospital-onset infection, although the appropriateness of antibiotic therapy within 36 h and the CAS were not identified as predictors. The CAS increased the proportion of appropriate antimicrobial therapy during the 24-36 h interval after bacteremia onset in patients with S. aureus BSIs.

Community-associated Panton-Valentine leukocidin-negative meticillin-resistant Staphylococcus aureus clone (ST72-MRSA-IV) causing healthcare-associated pneumonia and surgical site infection in Korea.

BACKGROUND: Community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as an important pathogen worldwide in a continent-specific manner. Clinical characteristics of infections caused by CA-MRSA other than USA300, especially in healthcare settings, have not been well established. AIM: To conduct a retrospective cohort study to determine the clinical characteristics of infections caused by Panton-Valentine leukocidin (PVL)-negative, multilocus sequence type (ST) 72 staphylococcal cassette chromosome mec (SCCmec) type IV, a major CA-MRSA clone in Korea. METHODS: ST72-IV isolates, which were susceptible to fluoroquinolones, gentamicin, rifampicin, and cotrimoxazole, were presumptively identified among 4667 MRSA isolates and then confirmed by SCCmec typing and multilocus sequence typing. A total of 124 cases of ST72-IV infections were analysed. FINDINGS: The annual incidence of infections by ST72-IV per 100,000 admissions increased from 45.5 to 66.3 cases during 2007-2009. The most frequently occurring type of infection was skin and soft tissue infection (SSTI) (46.0%), followed by pneumonia (27.4%) and bone and joint infection (9.7%). Surgical site infection accounted for 22.6% and 32.5% of community-onset (CO) healthcare-associated infection and hospital-onset (HO) infection, respectively. Pneumonia was most frequent (45.0%) among HO infection. Multivariate analysis showed that pneumonia increased the odds of all-cause mortality (odds ratio: 18.8; 95% confidence interval: 2.6-133.9) compared with other types of infection. CONCLUSIONS: Increasing trends were observed in annual incidence of CO and HO infections by ST72-IV in Korea. Pneumonia was the most frequent among HO infection and was associated with higher mortality. These findings pose important implications for successful antibiotic therapy and infection control in the era of CA-MRSA.

Tacrolimus as a risk factor for tuberculosis and outcome of treatment with rifampicin in solid organ transplant recipients.

BACKGROUND: The purpose of this study was to investigate the incidence, risk factors, and treatment outcome of tuberculosis (TB) in solid organ transplant (SOT) recipients treated with rifampicin. METHODS: The incidence density of TB was calculated by a retrospective cohort study. Risk factors for TB were analyzed by a nested case-control study. Treatment outcome and effects of anti-TB drugs on immunosuppressants and allograft were compared between patients whose initial 2-month intensive regimen included rifampicin and those whose intensive regimen did not. RESULTS: Among the 2144 SOT recipients over 16 years, 40 cases of TB were found (1.7%). The incidence density was 372 cases per 10(5) patient years (95% confidence interval [CI], 270-503), which was 4 times higher than for the general Korean population (90 cases per 10(5) person years). The median time to the development of TB was 234 days (range, 33-3940 days). The use of tacrolimus (odds ratio [OR] 4.90; 95% CI, 1.74-13.80; P = 0.003) and cytomegalovirus (CMV) infection within the prior 3 months (OR 4.62; 95% CI, 1.44-14.87; P = 0.01) were found to be risk factors for TB. Patients whose intensive regimen included rifampicin were more likely to have an increased dose of calcineurin inhibitors than patients whose intensive regimen did not include rifampicin (13/15 [86.7%] vs. 3/14 [21.4%], P = 0.001). Graft rejection and mortality did not differ between the 2 groups. CONCLUSIONS: Use of tacrolimus and CMV infection were major risk factors for TB in SOT recipients. The graft outcome and mortality did not differ whether rifampicin was used or not during the first 2-month intensive phase.

Impact of inappropriate empiric antimicrobial therapy on outcome in Pseudomonas aeruginosa bacteraemia: a stratified analysis according to sites of infection.

BACKGROUND: The purpose of this study was to evaluate the impact of inappropriate empiric antimicrobial therapy on the outcome of Pseudomonas aeruginosa bacteraemia according to the primary infection site. METHODS: A retrospective cohort study including 202 patients with P. aeruginosa bacteraemia was performed. High-risk sites of infection were defined as the lung, intra-abdominal non-hepatobiliary tract or unknown source. RESULTS: Of the 202 patients with P. aeruginosa bacteraemia, 80 (39.6%) had received inappropriate empiric antimicrobial therapy. No significant difference in the 30-day mortality rate was found between the inappropriate therapy group and the appropriate therapy group (19/80 [23.8%] vs. 32/122 [26.2%], P = 0.692). Patients with pneumonia or non-hepatobiliary tract intra-abdominal infection showed significant association with high mortality, while those with urinary tract or hepatobiliary tract infection showed negative associations with mortality. In the subgroup analysis including 98 patients with high-risk sites of infection, the mortality rate of the inappropriate therapy group was significantly higher than that of the appropriate therapy group (14/26 [53.8%] vs. 23/72 [31.9%], P = 0.035). Inappropriate empiric antimicrobial therapy was also found to be one of the independent risk factors for mortality in patients with high-risk sites of infection (odds ratio [OR] 8.69; 95% confidence interval [CI] 1.86-40.59), along with renal disease, corticosteroid use, polymicrobial infection and higher Pitt bacteraemia score. CONCLUSION: Inappropriate empiric antimicrobial therapy adversely affected the outcome of P. aeruginosa bacteraemia in patients with high-risk sites of infection. Our data suggest that the impact of inappropriate antimicrobial therapy on the outcome of P. aeruginosa bacteraemia may be dependent on the primary site of infection.

Dysbindin gene variants are associated with bipolar I disorder in a Korean population.

The dysbindin gene (DTNBP1) has been associated with schizophrenia in several populations. Because the clinical characteristics of schizophrenia and bipolar disorder overlap in many respects and findings from genetic studies have suggested common genes between them, we conducted a case control association study of bipolar disorder in Korea to investigate the genetic association between DTNBP1 and bipolar disorder. In total, 163 patients with bipolar disorder and 350 controls were evaluated. We genotyped three single nucleotide polymorphisms of DTNBP1 (SNP A, P1763, and P1320) and analyzed the allele, genotype, and haplotype associations with bipolar disorder. We found significant genotypic associations with P1763 and P1320, but no association with SNP A in the bipolar I group. When we included bipolar II and schizoaffective disorder in the affected phenotype, the significance decreased. A positive association was observed between the SNP A-P1763 haplotype and the bipolar I phenotype. This haplotype association was lost when we either broadened our phenotype or included P1320 in a haplotype. The positive results of the present study lost significance after a Bonferroni correction for multiple testing. These findings are consistent with previous findings that showed a positive association of DTNBP1 with bipolar disorders. Moreover, our results suggest that DTNBP1 may contribute more to bipolar I disorder than bipolar II disorder or schizoaffective disorder. Further comprehensive studies will be required to clarify these association, however, it seems likely that DTNBP1 is a susceptibility gene for bipolar disorder.

Melanocortin 3 receptor (MC3R) gene variants in extremely obese women.

OBJECTIVE: Following several reports of linkage of obesity related phenotypes to human chromosome 20q we sought to determine whether variations of the melanocortin 3 receptor (MC3R) gene are associated with obesity. DESIGN: We screened the MC3R gene coding region and approximately 2 kb of 5' and 3' flanking sequences for DNA variants in unrelated extremely obese women and average weight controls using polymerase chain reaction (PCR) single strand conformation polymorphism (SSCP) analysis and DNA sequencing. SUBJECTS: 124 unrelated extremely obese women (body mass index, (BMI)>/=40 kg/m2) and 85 average weight controls (BMI<27 kg/m2). MEASUREMENTS: Radiation hybrid (RH) mapping was performed to localize the MC3R gene. 5' and 3' flanking sequences of MC3R gene were cloned. PCR-SSCP and DNA sequencing were used to detect mutations in the MC3R gene coding region and flanking sequences. RESULTS: RH mapping localized the MC3R gene to 20q13, between markers D20S100 and D20S149. 1083 bp 5' and 653 bp 3' flanking region of the MC3R gene were cloned. A missense mutation (+241, codon 81 ATT/GTT, Ile-->Val) was found in the MC3R coding region. Four more variants were detected in the 5' flanking sequence: -201(C-->G), -239 (A-->G), -762(A-->T) and -769(T-->C). Compared with controls, no significant allele frequency differences were found. Racial differences were found for the +241, -201, -239 and -762 polymorphisms. CONCLUSIONS: Several sequence variants were found in the MC3R gene coding region and in 5' flanking sequences. However, none of the variants were associated with obesity phenotypes. The linkage of extreme human obesity on 20q13 is likely caused by genes other than MC3R. International Journal of Obesity (2000) 24, 206-210

Possible association between schizophrenia and a CAG repeat polymorphism in the spinocerebellar ataxia type 1 (SCA1) gene on human chromosome 6p23.

The gene for spinocerebellar ataxia type 1 (SCA1) is a potential candidate gene for schizophrenia because of previous positive linkage findings in this region (6p22-24), and because the reported correlation between SCA1 onset and the number of CAG repeats suggests anticipation. To test the involvement of this gene in the development of schizophrenia, we examined genotypes of the SCA1 CAG repeat polymorphism for 49 Caucasian patients with schizophrenia, and 88 Caucasian controls. We found a significant association between the frequencies of alleles of this gene and schizophrenia (chi 2 = 18.40, df = 8, P = 0.018). Among 13 alleles, one allele (31 trinucleotide repeat) was significantly more frequent in patients with schizophrenia than in controls (chi 2 = 9.57, df = 1, P = 0.002). This association was sustained after applying a Bonferroni correction for multiple testing (P = 0.05/13 = 0.004), and the chi-square results were shown to be robust through Monte Carlo simulation. We observed no allelic association with three flanking microsatellite markers (D6S288, D6S1605, and D6S337), suggesting that our result was not due to population stratification. Further studies of this locus are needed to confirm this finding, and to determine a potential role for this gene in the development of schizophrenia.

Genome scan for human obesity and linkage to markers in 20q13.

Obesity is a highly prevalent, multigenic trait that predicts increased morbidity and mortality. Here we report results from a genome scan based on 354 markers in 513 members of 92 nuclear families ascertained through extreme obesity and normal body weight. The average marker interval was approximately 10 cM. We examined four correlated obesity phenotypes, including the body-mass index (BMI) (both as a quantitative trait and as a discrete trait with a threshold of BMI > or /=30 kg/m2) and percentage of fat (both as a quantitative trait and as a discrete trait with a threshold of 40%) as assessed by bioelectrical impedance. In the initial stage of the genome scan, four markers in 20q gave positive evidence for linkage, which was consistent across most obesity phenotypes and analytic methods. After saturating 20q with additional markers (25 markers total) in an augmented sample of 713 members from 124 families, we found linkage to several markers in a region, 20q13, previously implicated in both human and animal studies. Three markers (D20S107, D20S211, and D20S149) in 20q13 had empirical P values (based on Monte Carlo simulations, which controlled for multiple testing) < or /=. 01 for single-point analysis. In addition, the parametric, affecteds-only analysis for D20S476 yielded a LOD score of 3.06 (P=. 00009), and the affected-sib-pair test yielded a LOD score of 3.17 (P=.000067). Multipoint analyses further strengthened and localized these findings. This region includes several plausible candidate genes for obesity. Our results suggest that one or more genes affecting obesity are located in 20q13.