Association between Pneumonia Development and Virulence Gene Expression in Carbapenem-Resistant Acinetobacter baumannii Isolated from Clinical Specimens

We investigated the virulence gene expression of carbapenem-resistant Acinetobacter baumanii (CRAB) isolated from the respiratory samples of patients with CRAB pneumonia and those with CRAB colonization to identify the virulence genes contributing to CRAB pneumonia's development and mortality. Patients with CRAB identified from respiratory specimens were screened at a tertiary university hospital between January 2018 and January 2019. Patients were classified into CRAB pneumonia or CRAB colonization groups according to predefined clinical criteria. A. baumannii isolated from respiratory specimens was examined for the expression levels of ompA, uspA, hfq, hisF, feoA, and bfnL by quantitative reverse-transcription polymerase chain reaction. Among 156 patients with CRAB from respiratory specimens, 17 and 24 met the criteria for inclusion in the pneumonia and colonization groups, respectively. The expression level of ompA was significantly higher in the pneumonia group than in the colonization group (1.45 vs. 0.63, P=0.03). The expression levels of ompA (1.97 vs. 0.86, P=0.02), hisF (1.06 vs. 0.10, P < 0.01), uspA (1.62 vs. 1.01, P < 0.01), and bfnL (3.14 vs. 2.14, P=0.03) were significantly higher in patients with 30-day mortality than in the surviving patients. Elevated expression of hisF (adjusted odds ratio = 5.93, P=0.03) and uspA (adjusted odds ratio = 7.36, P=0.02) were associated with 30-day mortality after adjusting for age and the Charlson score. uspA and hisF may serve as putative targets for novel therapeutic strategies.

1855. Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteremia

Background

Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia occur within a few days after the onset of bacteremia, risk factors for early mortality (EM) have not been deeply investigated. We aimed to determine the risk factors for EM and the difference between risk factors associated with EM and late mortality (LM) in CRAB bacteremia.

Methods

All patients with CRAB bacteremia in 10 hospitals during a 1-year study period were identified. We prospectively collected patients’ clinical data, including microbiological and demographic data, underlying comorbidities, origin of bacteremia, severity of illness, antibiotic therapy, and mortality. Among the cases with mortality within 30 days, EM and LM were defined as death within 3 and more than 5 calendar days from the first positive blood culture, respectively.

Results

A total of 212 CRAB bacteremia cases were included in the analysis. Of 122 (57.5%) patients with 30-day mortality, EM was observed in 75 (61.5%) patients and LM in 39 (32.0%) patients. The proportion of severe sepsis or septic shock, Pitt score, and Sequential Organ Failure Assessment (SOFA) score were significantly higher in 30-day deaths than 30-day survivors. These factors of clinical severity were also significantly higher in patients with EM than those with LM. While urinary tract infection as the factor of site of infection and the severity of illness were independent predictors of LM, only factors representing the severity of illness were independent risk factors for EM. Appropriate empirical antibiotic therapy was associated with reduced risk of EM.

Conclusion

The difference between risk factors for EM and LM was identified in this study. Our data suggest that a large proportion of CRAB bacteremia with high severity progress to a rapidly fatal course, regardless of the underlying diseases or source of infection. Further studies might be needed to investigate the microbiological factors associated with CRAB and pathogen-host interaction in patients with EM.

Disclosures

All Authors: No reported disclosures.

Clinical and economic burden of bacteremia due to multidrug-resistant organisms in Korea: a prospective case control study

OBJECTIVES

The socioeconomic and clinical burden of multidrug-resistant organisms (MDRO), including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), multidrug-resistant Acinetobacter baumannii (MRAB), multidrug-resistant Pseudomonas aeruginosa (MRPA), and carbapenem-resistant Enterobacteriaceae (CRE) have not yet been adequately addressed.

METHODS

We prospectively searched for MDRO bacteremia cases with matched controls from 10 hospitals across Korea during a 6-month period in 2017. Patients were classified into the MDRO, susceptible organism, and no-infection groups. The corresponding susceptible or no-infection controls had been selected according to predefined criteria. We collected clinical information and estimated the total additional medical cost due to MDRO infections using the multistate model.

RESULTS

During the 6-month period, a total of 486 MDRO bacteremia cases (260, 87, 18, 20, and 101 cases of MRSA, MRAB, MRPA, CRE, and VRE, respectively) were identified. The 90-d mortality rates were 30.4%, 63.2%, 16.7%, 55.0%, and 47.5%, respectively. The additional costs caused by bacteremia were $15 768, $35 682, $39 908, $72 051, and $33 662 per MDRO type, respectively. Based on these 6-month data, the estimated annual number of bacteremia cases due to these five MDRO in Korea were 7979 (4070, 1396, 218, 461, and 1834 cases, respectively). Overall, this caused an estimated 3280 (1237, 882, 36, 254, and 871, respectively) deaths and cost $294 505 002 ($84 707 359, $74 387 364, $10 344 370, $45 850 215, and $79 215 694, respectively) (range $170,627,020-$416,094,679) in socioeconomic loss.

CONCLUSIONS

A tremendous clinical and economic burden is caused by MDRO bacteremia compared with antibiotic-susceptible and no-infection groups. Substantial investment and efforts by related government agencies and medical staffs are needed.

Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteraemia

OBJECTIVES

Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteraemia occur within a few days after the onset of bacteraemia, risk factors for early mortality (EM) have not been deeply investigated. We aimed to determine the risk factors for EM and the difference between risk factors associated with EM and late mortality (LM) in CRAB bacteraemia.

METHODS

Clinical information on all patients with CRAB bacteraemia in 10 hospitals during a 1-year period was collected. Among the cases with mortality within 30 days, EM and LM were defined as death within 3 and more than 5 calendar days from the first positive blood culture, respectively.

RESULTS

In total, 212 CRAB bacteraemia cases were included in the analysis. Of 122 (57.5%) patients with 30-day mortality, EM was observed in 75 (61.5%) patients and LM in 39 (32.0%) patients. The proportion of severe sepsis or septic shock, Pitt score, and Sequential Organ Failure Assessment (SOFA) score was significantly higher in patients with EM than those with LM. Although urinary tract infection as the site of infection and the severity of illness were independent predictors of LM, only factors representing the severity of illness were independent risk factors for EM.

CONCLUSION

Our results suggest that a large proportion of CRAB bacteraemia with high severity progresses to a rapidly fatal course, regardless of the underlying diseases or source of infection. Further studies might be needed to investigate the microbiological factors associated with CRAB and pathogen-host interaction in patients with EM.

Comparison of Three Cardiovascular Risk Scores among HIV-Infected Patients in Korea: The Korea HIV/AIDS Cohort Study

Background

We investigated cardiovascular disease (CVD), risk factors for CVD, and applicability of the three known CVD risk equations in the Korean human immunodeficiency virus/ Acquired Immune Deficiency Syndrome (HIV/AIDS) cohort.

Materials and Methods

The study parcitipants were HIV-infected patients in a Korean HIV/AIDS cohort enrolled from 19 hospitals between 2006 and 2017. Data collected at entry to the cohort were analyzed. The 5-year CVD risk in each participant was calculated using three CVD risk equations: reduced CVD prediction model of HIV-specific data collection on adverse effects of anti-HIV drugs (R-DAD), Framingham general CVD risk score (FRS), and Korean Coronary Heart Disease Risk Score (KRS).

Results

CVD events were observed in 11 of 586 HIV-infected patients during a 5-year (median) follow-up period. The incidence of CVD was 4.11 per 1,000 person-years. Older age (64 vs. 41 years, P = 0.005) and diabetes mellitus (45.5% vs. 6.4%, P <0.001) were more frequent in patients with CVD. Using R-DAD, FRS, and KRS, 1.9%, 2.4%, and 0.7% of patients, respectively, were considered to have a very high risk (≥10%) of 5-year CVD. The discriminatory capacities of the three prediction models were good, with c-statistic values of 0.829 (P <0.001) for R-DAD, 0.824 (P <0.001) for FRS, and 0.850 (P = 0.001) for KRS.

Conclusion

The FRS, R-DAD, and KRS performed well in the Korean HIV/AIDS cohort. A larger cohort and a longer period of follow-up may be necessary to demonstrate the risk factors and develop an independent CVD risk prediction model specific to Korean patients with HIV.

1006. Association of Development of Pneumonia and Virulence Gene Expression in Acinetobacter baumannii Isolated from Clinical Specimens

Background

Not all Acinetobacter baumannii isolated from respiratory specimens are true pathogens. Distinguishing between true pathogens and colonizers is important to initiate early treatment and to reduce the unnecessary prescription of antibiotics. To determine the microbiological factors contributing to the development of A. baumannii pneumonia, we investigated the association between the expression level of known A. baumannii virulence genes such as ompA and hisF and pneumonia.

Methods

Patients in whose respiratory specimens A. baumannii was identified between January 2018 and January 2019 in a tertiary university hospital were recruited into this study. Relevant radiologic findings and more than 5 days of susceptible antibiotic prescription started within 3 days of bacterial isolation were considered as having pneumonia. The absence of radiologic findings of pneumonia until 7 days after the isolation of A. baumannii was defined as colonization. The expression of ompA and hisF was determined with quantitative reverse-transcription polymerase chain reaction. Host factors known to be associated with pneumonia and expression levels of virulent genes were compared between the groups.

Results

Overall, 246 patients in whose respiratory specimens A. baumannii was identified were recruited into this study. Among them, 17 and 24 patients were assigned to the pneumonia and colonizer groups, respectively. In the univariable analysis, ompA, ICU stay, and mechanical ventilation were significantly associated with pneumonia (p = 0.03, &lt; 0.01, &lt; 0.01 respectively). In the multivariable analysis, mechanical ventilation was significantly associated with pneumonia (OR = 9.75, p = 0.03). ompA expression was not significantly associated with pneumonia in the multivariable analysis (OR = 1.12, p = 0.75) (Table 1). ompA and hisF were significantly associated with the 30-day in-hospital mortality (p = 0.02, &lt; 0.01).

Table 1. Univariable and multivariable analysis of factors related to pneumonia

Conclusion

The association between increased ompA expression in A. baumannii and the development of pneumonia was not statistically significant after adjusting for patient factors. However, the relatively high expression of ompA in pneumonia patients and their association with increased mortality suggests the need for larger-scale prospective studies to draw a conclusion.

Disclosures

All Authors: No reported disclosures

Recurrent meningococcal meningitis with complement 6 (C6) deficiency: A case report

RATIONALE

Late complement deficiency increases susceptibility to meningococcal disease and recurrent infections. In Korea, 5 case reports have described meningococcal disease with complement deficiency. However, C6 deficiency has not been described previously.

PATIENT CONCERNS

A 21-year-old police trainee presented with recurrent meningococcal meningitis. He was housed in communal living quarters until 20 days before the initial symptom onset.

DIAGNOSIS

He was diagnosed with meningococcal meningitis with C6 deficiency.

INTERVENTIONS

He was treated with intravenous ceftriaxone. An additional dose of quadrivalent meningococcal conjugate vaccine was administered after discharge.

OUTCOMES

He was discharged without complications.

LESSONS

Screening for complement deficiency is necessary in patients with a history of recurrent meningococcal infections to provide appropriate care and prevent recurrent infections.

Comparison of pyogenic postoperative and native vertebral osteomyelitis

BACKGROUND CONTEXT

Postoperative vertebral osteomyelitis (PVO) after spinal surgery is a clinical challenge. However, there is a paucity of evidence regarding the most likely etiologic organisms to guide the choice of empirical antibiotic therapy, and previous reports of treatment outcomes for PVO are scarce.

PURPOSE

To compare the microbiology, clinical characteristics, and outcomes of pyogenic PVO with native vertebral osteomyelitis (NVO).

STUDY DESIGN

Retrospective comparative study.

PATIENT SAMPLE

Patients with microbiologically proven vertebral osteomyelitis from three university-affiliated hospitals in South Korea between January 2005 and December 2015 with follow-up of at least 12 months after completion of antibiotics or until the patient was transferred. Patients who had a spine operation in the same location within 1 year of diagnosis, and all patients with remnant implants at the time of the vertebral osteomyelitis diagnosis, were defined as having PVO. The remainder of the patients was considered to have NVO. Spinal operations included discectomy, laminectomy, arthrodesis, and instrumentation for stabilization of the spine.

OUTCOME MEASURES

Overall mortality, neurologic outcomes, treatment failure, and relapse of infection.

METHODS

Demographic data, comorbidities, presenting symptoms, microbiological data, radiographic characteristics, laboratory data (including white blood cell counts, erythrocyte sedimentation rate, and C-reactive protein), surgical treatment, and neurologic outcomes for each patient were reviewed from electronic medical records and analyzed. Mortality rate, treatment failure, and relapse of infection were calculated for the two groups. Factors associated with treatment outcome were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

The study evaluated 104 patients with PVO and 441 patients with NVO. In PVO, the most common isolate was Staphylococcus aureus (34%, n=35), followed by coagulase-negative staphylococci (31%, n=32). In NVO, the most common isolates were S. aureus (47%, n=206) and streptococci (21%, n=94). Of the staphylococci, the proportion of methicillin-resistant strains was significantly higher in PVO than that in NVO (75% vs. 39%, p<.001). The proportion of patients with gram-negative bacilli was 14% in PVO and 20% in NVO. Pre-existing or synchronous nonspinal infection was observed more frequently in NVO than in PVO (33% vs. 13%, p<.001). Although the duration of antibiotic use was similar in both groups, surgery for infection control was performed more frequently in PVO. The mortality rate was similar in both groups. However, the treatment failure and relapse rates at 12 months were higher in the PVO group (23% vs. 13%, p=.009; 14% vs. 7%, p=.028, respectively). Methicillin-resistant S.aureus was significantly associated with treatment failure or relapse via logistic regression (odds ratio 3.01, 95% confidence interval [1.71-5.32], p<.001; odds ratio 2.78, 95% confidence interval [1.40-5.49], p=.003).

CONCLUSIONS

Coverage of methicillin-resistant staphylococci should be considered when prescribing empirical antibiotics for PVO. Although surgery was performed more often in PVO than NVO, the treatment failure and relapse rates at 12 months were higher in PVO.

1056. Predicting Central Nervous System Complications in Staphylococcus aureus Bacteremia Using Clinical Scoring System

Background

Central nervous system (CNS) complications occurring in patients with Staphylococcus aureus bacteremia (SAB) are the most severe complications. In this study, we compared clinical data of SAB patients between cases with and without CNS complication and analyzed the risk factor of CNS complications.

Methods

Data from cases with SAB occurred during 5 years at four hospitals were collected. The presence of CNS complications was confirmed by brain MRI, CT, or lumbar puncture. We excluded the cases who already had CNS lesions such as trauma, brain tumor, or cerebrovascular accident. We also excluded the cases who were died or transfer out &lt;7 days of bacteremia onset. Cases were divided into complication group or noncomplication group according to the presence of CNS complication. We compared the clinical profiles between the groups, and analyzed the risk factor of CNS complications by multivariate logistic regression analysis.

Results

A total of 1,085 cases of SAB patients were included. Among these, 43 (4%) cases were complication group (embolic infarct [n = 23], brain hemorrhage [n = 8], infarct with hemorrhage [n = 8], and brain abscess or meningitis [n = 4]), while 810 (74%) cases were noncomplication group. Two hundred and forty-one cases were excluded. The results of multivariate analysis were shown in table. When selecting by having less than three factors among SOFA &gt; 5, methicillin-susceptible, endovascular infection (weight 2), presence of metastatic infection and community onset, it helps to exclude CNS complications (AUC of ROC curve = 0.77, P &lt; 0.01, sensitivity; 67.5%, specificity: 75.5%, positive predictive value: 12.9%, negative predictive value 97.7%).

Conclusion

CNS complication could be excluded by using clinical variables

Disclosures

All authors: No reported disclosures.

294. Spondylodiscitis After Spine Surgery: Microbiology, Clinical Findings, Outcome and Comparison With Spontaneous Spondylodiscitis

Background

Although postoperative spondylodiscitis has become a major problem, consensus on empirical antibiotics therapy is still controversial. To find out appropriate management of postoperative spondyodiscitis, this study investigated the microbiology, clinical characteristics, and outcome of postoperative pyogenic spondylodiscitis (P-PS) and compared with spontaneous pyogenic spondylodiscitis (S-PS).

Methods

This retrospective cohort study evaluated patients with microbiologically proven spondylodiscitis from three university-affiliated hospitals in South Korea between January 2005 and December 2015, with a follow-up of at least 12 months after completion of antibiotics or until the patient was transferred. Patients with prosthesis at the time of diagnosis of spondylodiscitis or who had a spine operation within 1 year of the diagnosis of spondylodiscitis were defined as having postoperative spondylodiscitis. The spine operations included discectomy, laminectomy, arthrodesis, and instrumentation for stabilization of the spine.

Results

The study evaluated 104 patients with P-PS and 441 patients with S-PS. In P-PS, the most common isolate was S. aureus (34%), followed by coagulase-negative staphylococci (31%), and the proportion of methicillin-resistant strains was 75%. In S-PS, the most common isolates were S. aureus (47%) and streptococci (21%). Of the staphylococci, 39% were methicillin resistant in S-PS. The proportion of patients with Gram-negative bacilli was 14% in P-PS and 20% in S-PS. Pre-existing or synchronous nonspinal infection (13% vs. 33%, P < 0.001) was observed more frequently in S-PS. Although the duration of antibiotic use was similar in both groups, surgical procedures were done more frequently in P-PS. The mortality rate was similar in both groups. However, the treatment failure and relapse rates at 12 months were higher in the P-PS group (23% vs. 13%, P = 0.009; 14% vs. 7%, P = 0.028, respectively). Methicillin-resistant S. aureus was associated with treatment failure or relapse.

Conclusion

Gram-positive organisms, mainly methicillin-resistant staphylococci, should be considered when prescribing empirical antibiotics in P-PS. Although surgical drainage was applied more often in P-PS than in S-PS, the treatment failure and relapse rates at the 12-month follow-up were higher in P-PS.

Disclosures

All authors: No reported disclosures.

Risk factors for poor outcome in community-onset Clostridium difficile infection

Background

A substantial portion of Clostridium difficile infection (CDI) cases occur in communities, and community-onset CDI (CO-CDI) can lead to serious complications including mortality. This study aimed to identify the risk factors for a poor outcome in CO-CDI.

Methods

We performed a retrospective review of all inpatients with CDI, in a 1300-bed tertiary-care hospital in Korea, from 2008 through 2015. CO-CDI was defined as CDI occurring within 48 h of admission. Poor outcome was defined as follows: 1) all-cause 30-day mortality, 2) in-hospital mortality, or 3) surgery due to CDI.

Results

Of a total 1256 CDIs occurring over 8 years, 152 (12.1%) cases were classified as CO-CDI and 23 (15.1%) had a poor outcome, including 22 (14.5%) cases of mortality and 2 (1.3%) cases of surgery. Patients with a poor outcome had a higher mean age than those without a poor outcome (75.8 vs. 69.6 years, p = 0.03). The proportion of men and prior proton pump inhibitor (PPI) use were significantly higher in the poor outcome group (65.2% vs. 41.9%, p = 0.04; 39.1% vs. 17.6%, p = 0.02, respectively). Multivariate binary logistic model showed that PPI use and anemia (hemoglobin < 10 g/dL) at presentation were significantly associated with a poor outcome (adjusted odds ratio [aOR], 3.76; 95% confidence interval [95CI], 1.26-11.21, aOR, 4.67; 95CI, 1.52-14.34, respectively).

Conclusions

Clinicians should not only be aware of the possibility of CDI in the community setting but also pay more attention to PPI-using elderly patients with anemia in consideration of a poor outcome.

Effect of an intervention targeting inappropriate continued empirical parenteral vancomycin use: a quasi-experimental study in a region of high MRSA prevalence

Background

Despite vancomycin use is a major risk factor for the emergence of vancomycin resistance, it is frequently inappropriately prescribed, especially as empirical treatment. We evaluated the effect of an antimicrobial stewardship intervention targeting for inappropriate continued empirical vancomycin use.

Methods

This was a quasi-experimental study comparing vancomycin use in a 6-month pre-intervention and 6-month intervention period. If empirical vancomycin was continued for more than 96 h without documentation of beta-lactam-resistant gram-positive microorganisms, it was considered inappropriate continued empirical vancomycin use. The intervention consisted of the monitoring of appropriateness by a pharmacist and direct discussion with the prescribing physicians by infectious disease specialists when empirical vancomycin was continued inappropriately. An interrupted time series analysis was used to compare vancomycin use before and during the intervention.

Results

Following implementation of the intervention, overall vancomycin consumption decreased by 14.6%, from 37.6 defined daily doses (DDDs)/1000 patient-days in the pre-intervention period to 32.1 DDDs/1000 patient-days in the intervention period (P <  0.001). The inappropriate consumption of vancomycin also declined from 8.0 DDDs/1000 patient-days to 5.8 DDDs/1000 patient-days (P = 0.009).

Conclusion

Interventions such as direct communication with prescribing physicians and infectious disease clinicians can help reduce the inappropriate continued use of vancomycin.

Sudden Deaths of Neonates Receiving Intravenous Infusion of Lipid Emulsion Contaminated with Citrobacter freundii

At an intensive care unit, four neonates died consecutively within 80 minutes. Citrobacter freundii was isolated from blood samples of the 4 patients. It was also cultured from the leftover SMOFlipid that had been infused intravenously into the patients. In this in vitro study, we evaluated the bacterial growth kinetics and change in size of fat globules in SMOFlipid contaminated with C. freundii. Following the growth of bacteria, pH of SMOFlipid decreased to < 6, and the number of fat globules larger than 5 μm increased. Pulmonary fat embolism is proposed as a possible cause of the sudden deaths as well as fulminant sepsis.

Active surveillance for carbapenem-resistant Enterobacteriaceae, vancomycin-resistant enterococci and toxigenic Clostridium difficile among patients transferred from long-term care facilities in Korea

A 10-month active surveillance study was conducted to assess carriage of carbapenemase-producing Enterobacteriaceae (CPE), vancomycin-resistant enterococci (VRE) and toxigenic Clostridium difficile colonization among patients transferred to hospital from long-term care facilities (LTCFs). Four (1.4%) patients with carbapenem-resistant Enterobacteriaceae (none of which were CPE), 59 (21%) patients with VRE and 20 (7.1%) patients colonized with toxigenic C. difficile were identified from 282 rectal specimens. There was no outbreak of VRE infection during the study period. The low prevalence of CPE carriage suggests that screening all admissions from LTCFs for CPE would not be cost-effective, and that screening and use of contact precautions for VRE should be reconsidered.

Analysis of the number of enlarged pores according to site, age, and sex

BACKGROUND

Increasing the number of enlarged pores causes cosmetic problems. The difference in the number of enlarged pores according to facial site, age, and sex is unclear.

OBJECTIVE

To analyze the distribution of the number of enlarged pores according to facial site, age, and sex.

METHODS AND MATERIALS

We analyzed the number of the enlarged pores and the percentage of wrinkles in the nose, forehead, and cheek from 434 polarized images. The measurement results were analyzed according to site, age, and sex. Relationship between enlarged pore counts and wrinkle severity was also analyzed. The study was conducted by using DermaVision,™ which can take cross-polarization, parallel polarization, and ultraviolet light images.

RESULTS

The enlarged pores of the nose and forehead were more prominent than in the cheeks. Pore counts were increased with age, and the increment was significant between the 30's and 40's. There was no significant difference by gender. Enlarged pore counts were related to wrinkle severity.

CONCLUSIONS

The number of enlarged pores differs depending on body site and increased with age. The enlarged pore counts correlate with wrinkle severity and the correlation varies depending on the body site.

Concordance of Results of Blood and Tissue Cultures from Patients with Pyogenic Spondylitis

Background

The aim of this study was to investigate the concordance of results of blood and tissue cultures in patients with pyogenic spondylitis.

Methods

We searched the patients with pyogenic spondylitis in whom micro-organisms were isolated from both blood and tissue cultures by retrospective review of medical records in three tertiary university-affiliated hospitals between January 2005 and December 2015. The species and antimicrobial susceptibility patterns of isolates from blood and tissue cultures were compared with each other.

Results

Among 141 patients with pyogenic spondylitis in whom micro-organisms were isolated from both blood and tissue cultures, the species of blood and tissue isolates were identical in 135 patients (95.7%, 135/141). Excluding the four anaerobic isolates, we investigated antimicrobial susceptibility patterns of 131 isolates of same species from blood and tissue cultures. Antibiotic susceptibility patterns were identical in 128 patients (97.7%, 128/131). The most common isolates were Staphylococcus aureus (86 patients; 85 concordant and 1 discordant), followed by streptococcus (24 patients; 22 concordant and 2 discordant), and Escherichia coli (8 patients; all concordant).

Conclusion

We suggest that a positive blood culture from patients with pyogenic spondylitis could preclude the need for additional tissue cultures, especially when S. aureus and streptococcus grew in blood cultures.

Disclosures

All authors: No reported disclosures.

Concordance of results of blood and tissue cultures from patients with pyogenic spondylitis: a retrospective cohort study

OBJECTIVES

To investigate the concordance of results of blood and tissue cultures in patients with pyogenic spondylitis.

METHODS

We searched for patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures by retrospective review of medical records in three tertiary university-affiliated hospitals between January 2005 and December 2015. The species and antimicrobial susceptibility patterns of isolates from blood and tissue cultures were compared.

RESULTS

Among 141 patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures, the species of blood and tissue isolates were identical in 135 patients (95.7%, 135/141). Excluding the four anaerobic isolates, we investigated antimicrobial susceptibility patterns of 131 isolates of the same species from blood and tissue cultures. Antibiotic susceptibility patterns were identical in 128 patients (97.7%, 128/131). The most common isolates were Staphylococcus aureus (86 patients; 85 concordant and one discordant), followed by streptococcus (24 patients; 22 concordant and two discordant), and Escherichia coli (eight patients; all concordant).

CONCLUSIONS

We suggest that a positive blood culture from patients with pyogenic spondylitis could preclude the need for additional tissue cultures, especially when S. aureus and streptococcus grew in blood cultures.

Factors associated with the growth of ground-glass opacity nodules on chest computed tomography

e20051

Background: Chest computed tomography (CT) has become increasingly popular for screening and various reasons, and many cases of ground-glass opacity pulmonary nodules (GGN) that cannot be detected by simple chest radiography have been found incidentally. However, the natural history of GGN is not well understood and guidelines for the evaluation and follow-up of GGN have not yet been established yet. The purpose of this study was to investigate the clinical and CT scan characteristics associated with the growth of GGNs. Methods: We retrospectively reviewed GGN on chest CT performed between March 2011 and February 2014 at a tertiary referral hospital. Data were collected for the patient's age, sex, underlying lung disease, history of malignancy or comorbidities, size, border, number of GGN and presence of solid portion in GGN. For each GGN, an increase in size over time was investigated. We applied a Cox regression analysis to identify factors associated with the growth of GGN. Results: In a total of 504 patients, 916 GGN were found on chest CT. The mean age of the subjects was 59.6 years and 37% of men. The mean follow-up was 17.1 months. Cox regression analysis was performed on age, sex, history of malignancy, maximum diameter of GGN, number of GGN, margins of GGN, and presence of solid portion in GGN. History of malignancy (adjusted hazard ratio [HR] 1.770, 95% confidence intervals [CI] 1.049-2.986, p = 0.032), solitary nodule (adjusted HR 2.335, 95% CI 1.401-3.867, p = 0.001), and nodules with the longest diameter of 10 mm or more (adjusted HR 1.833, 95% CI 1.032-3.253, p = 0.039) were associated with the growth of GGN. Conclusions: A history of malignancy, solitary nodule, and nodules with the longest diameter of 10 mm or more may increase in size in the future. Therefore, the history of malignancy and the size and number of nodules should be considered to determine the duration of follow-up and appropriate biopsy timing.

Umbilical arterial N-terminal pro-B-type natriuretic peptide levels in preeclampsia, fetal growth restriction, preterm birth and fetal distress

OBJECTIVE

To evaluate fetal cardiopulmonary stress in pregnancies complicated by preeclampsia (PE), fetal growth restriction (FGR), preterm birth (PT), and fetal distress (FD) using umbilical arterial blood N-terminal pro-B-type natriuretic peptide (NT-proBNP).

MATERIALS AND METHODS

The study included 146 blood samples that were drawn from umbilical arteries at the time of delivery (20 cases of PE, 11 cases of FGR, 31 cases of PT, 23 cases of FD, and 61 cases of gestational age-matched controls) and analyzed. The main outcome measures included neonatal birthweight, cord pH, and umbilical arterial NT-proBNP.

RESULTS

The umbilical arterial NT-proBNP levels were significantly higher in the PE, FGR, PT, and FD groups than in the control group. The umbilical arterial NT-proBNP levels were negatively correlated with gestational age, birthweight, and umbilical arterial pH.

CONCLUSIONS

Umbilical arterial NT-proBNP levels are elevated in stressful fetal conditions and have the potential to be considered as a marker for fetal cardiopulmonary stress.

A case of prenatally diagnosed Uhl's anomaly

BACKGROUND

Uhl's anomaly is an extremely rare cardiac defect characterized by absence of the myocardium of the right ventricle. Until now, only three cases have been diagnosed or have showed suspicious diagnosis in prenatal period.

CASE

A 28-year-old nulliparous woman was referred to the present hospital for counseling the risk of drug medication. The authors found dilatation of the right ventricle and thinning of the right ventricular wall in the fetus at 25 weeks gestation. No other structural abnormalities were found concerning the great arteries and all heart valves demonstrated normal function. Uhl's anomaly was suspected on fetal echocardiography and it was confirmed postnatally by echocardiography and computed tomography (CT). The infant showed stable condition during neonatal period and is doing well in the ambulatory care after three-years follow up:

CONCLUSION

Although the outcomes of Uhl's anomaly are generally unfavorable, the duration of survival shows wide variation according to the cardiac function. To estimate the postnatal outcomes, it is highly recommended to perform the accurate differential diagnosis by using fetal echocardiography during pregnancy.

The influence of ritodrine alone or in combination with nifedipine on maternal cardiovascular side effects and pregnancy outcomes

OBJECTIVE

To compare the influence of ritodrine alone or in combination with nifedipine on maternal side effects and suppressing preterm labor.

MATERIALS AND METHODS

This retrospective study included 213 pregnancies with preterm labor (20-34 weeks) from May 2002 to April 2010 in Kyungpook National University Hospital in Daegu, Korea. Obstetric medical records were reviewed for both maternal characteristics and neonatal outcomes, including birth weight, Apgar score, admission to neonatal intensive care unit (NICU), ventilator support, and neonatal mortality. Maternal side effects such as tachycardia, pulmonary edema, and hyperglycemia were also reviewed.

RESULTS

Of 213 patients, 109 received ritodrine only and 104 were given ritodrine and nifedipine. There was no statistical difference between the two groups with regards to pregnancy outcomes and neonatal complications. Pregnancy prolongation over seven days was achieved more in the combination therapy group, with borderline statistical significance (59.6% vs. 72.1%, p = 0.055). Sixty-nine cases experienced maternal side effects; four cases were categorized as serious and 65 cases were mild.

CONCLUSION

In the treatment of preterm labor, the combination regimen of ritodrine and nifedipine can be more effective than ritodrine alone for prolonging gestation over seven days. Moreover, as the combination did not cause severe maternal side effects, it may be considered as a safe and effective method to prolong gestation in patients with preterm labor.

Variation in U.S. traffic safety policy environments and motor vehicle fatalities 1980-2010

OBJECTIVE

To examine the impact of variation in state laws governing traffic safety on motor vehicle fatalities.

STUDY DESIGN

Repeated cross sectional time series design.

METHODS

Fixed effects regression models estimate the relationship between state motor vehicle fatality rates and the strength of the state law environment for 50 states, 1980-2010. The strength of the state policy environment is measured by calculating the proportion of a set of 27 evidence-based laws in place each year. The effect of alcohol consumption on motor vehicle fatalities is estimated using a subset of alcohol laws as instrumental variables.

RESULTS

Once other risk factors are controlled in statistical models, states with stronger regulation of safer driving and driver/passenger protections had significantly lower motor vehicle fatality rates for all ages. Alcohol consumption was strongly associated with higher MVC death rates, as were state unemployment rates.

CONCLUSIONS

Encouraging laggard states to adopt the full range of available laws could significantly reduce preventable traffic-related deaths in the U.S. - especially those among younger individuals. Estimating the relationship between different policy environments and health outcomes can quantify the result of policy gaps.

Characterization of filamentous bacteriophage PE226 infecting Ralstonia solanacearum strains

AIMS

The aim of this study was to isolate and characterize new bacteriophages that infect a wide range of plant pathogenic Ralstonia solanacearum strains.

METHODS AND RESULTS

Fifteen bacteriophages were isolated from pepper, tomato and tobacco plant rhizospheres infected with R. solanacearum. A host specificity analysis of the isolated phages using nine strains of R. solanacearum indicated great phage diversity in a single soil. Two phages, PE226 and TM227, showed clear plaques on all nine bacterial hosts tested and were virtually identical in morphology and genome. PE226, an Inovirus, is a long, flexible, filamentous phage carrying a circular (+) sense single-strand DNA genome of 5475 nucleotides. DNA sequences of PE226 exhibited nine open reading frames (ORF) that were not highly similar to those of other phages infecting R. solanacearum. The genome organization of PE226 was partially similar to that of p12J of Ralstonia pickettii. One ORF of PE226 showed identity to the zot gene encoding zonula occludens toxin of Vibrio cholera. Orf7 of PE226 was also present in the genome of R. solanacearum strain SL341. However, SL341, a highly virulent strain in tomato, was still sensitive to phage PE226.

CONCLUSIONS

A new, flexible, filamentous phage PE226 infected wide range of R. solanacearum strains and carried unique circular single-strand DNA genome with an ORF encoding Zot-like protein.

SIGNIFICANCE AND IMPACT OF THE STUDY

PE226 may be a new type of temperate phage, based on its lytic nature on a wide range of hosts and the presence of a zot homologue in a host bacterial genome.

The distribution of inhibitory and excitatory synapses on single, reconstructed jaw-opening motoneurons in the cat

In a previous study, we reported that the distribution of inhibitory input, in contrast to excitatory input, decreased somatofugally along dendrites of cat jaw-closing alpha-motoneurons [J Comp Neurol 414 (1999) 454]. The present study examined the distribution of GABA, glycine, and glutamate immunopositive boutons covering horseradish peroxidase-labeled cat jaw-opening motoneurons. The motoneurons were divided into four compartments: the soma, and primary, intermediate, and distal dendrites. Ninety-seven percent of the total number of studied boutons had immunoreactivity for at least one of the three amino acids. The proportion of boutons immunoreactive for GABA and/or glycine was lower than the proportion of boutons immunoreactive for glutamate. Boutons immunoreactive to glycine alone were more numerous than boutons double-labeled for GABA and glycine, which, in turn, occurred more frequently than boutons immunoreactive to GABA alone. The percentage synaptic covering (proportion of membrane covered by synaptic boutons) of the putatively excitatory (glutamate containing) and putatively inhibitory (GABA and/or glycine containing) boutons decreased somatofugally along the dendrites. Such systematic variations were not seen in the packing density (number of boutons per 100 microm(2)); the packing density showed a distinct drop between the soma and primary dendrites but did not differ significantly among the three dendritic compartments. Overall, the packing density was slightly higher for the putatively excitatory boutons than for the inhibitory ones. When taken together with previous analyses of jaw-closing alpha-motoneurons the present data on jaw-opening alpha-motoneurons indicate that the two types of neuron differ in regard to the nature of synaptic integration in the dendritic tree.

Anaerobic digestion elutriated phased treatment of piggery waste

The performance of a novel high-rate anaerobic process, the anaerobic digestion elutriated phased treatment (ADEPT) process, for treating a slurry-type piggery waste (55 g COD/L and 37 g TS/L) was investigated. The ADEPT process consists of an acid elutriation slurry reactor for hydrolysis and acidification, followed by an upflow anaerobic sludge bed reactor for methanification. This process provides stable and high system performance with short HRT (7.4 d) and better effluent quality (2 g SCOD/L and 0.68 g VSS/L) due to the alkaline pH condition for hydrolysis/acidification phase, high refractory solids removal and ammonia toxicity reduction. The optimum pH and HRT for hydrolysis/acidogenesis of the piggery waste were 9 and 5 days at both 35 degrees C and 55 degrees C conditions. The hydrolysis and acidification rate in the mesophilic reactor were 0.05 d(-1) and 0.11 d(-1), meaning that hydrolysis was a limiting step. SCOD production by the hydrolysis was about 0.26 g SCOD/g VS(fed) (3.6 g SCOD/g VS reduction). Methane production and content in the system were 0.3 L CH4/g VS(fed) (0.67 L CH4/g VS destroyed) and 80%, respectively, corresponding to 0.23 L CH4/g COD removal (@STP).

Serum after partial hepatectomy stimulates iNOS gene transcription via downstream NF-kappa B site

It has been known that the expression of inducible nitric oxide synthase (iNOS) is up-regulated during hepatic regeneration. The present study characterized the molecular mechanisms involved in the transcriptional activation of iNOS gene by using the serum after partial hepatectomy (post-PH serum) in vitro. The post-PH serum rapidly induced iNOS mRNA expression, which was blocked by anti-tumor necrosis factor-alpha (TNF-alpha) antibody in BNL CL.2 cells, murine embryonic liver cell line. In addition, EMSAs using a NF-kappa B-specific oligomer showed that the up-regulated iNOS mRNA expression in cells treated with post-PH serum correlated with transient activation of NF-kappa B complex (p50/p65 heterodimer). Transient transfection of BNL CL.2 cells with iNOS promoter linked to a CAT reporter gene showed the transcriptional activation of iNOS promoter by post-PH serum. Furthermore, site-directed mutational analysis of the two NF-kappa B sites individually or in combination revealed that iNOS expression by post-PH serum is regulated by the downstream NF-kappa B site, but not by upstream NF-kappa B site. Taken together, these results suggest that the downstream NF-kappa B site acts as an essential component for the iNOS expression by post-PH serum during hepatic regeneration.

Diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread

A case of diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread is presented. The patient, an 18-year-old girl, was admitted due to progressive weakness and paresthesia of both legs, following rapid neuropsychiatric deterioration. An initial magnetic resonance imaging (MRI) study of the T-spine showed diffuse high signal intensities from T9 to T12 spinal cords on a T2 sagittal image and diffuse cord bulging at T1WI. This suggested an inflammatory lesion such as tuberculosis or fungal meningoencephalitis. A limited autopsy was performed. A microscopic examination revealed multifocal GFAP-positive astrocytic proliferations that were low grade astrocytoma in the cerebral leptomeninges, parietal, occipital and temporal lobes and anaplastic astrocytoma in the spinal cord and spinal leptomeninges. The high proliferative indices of the spinal lesion and aneuploidy correspond to a diagnosis of malignant astrocytoma and a rapid fatal clinical course.

Electroretinographic evaluation in adult diabetics

In cross-sectional fashion, we recorded the maximal combined response and 30-Hz flicker responses in 178 adult diabetics and 40 normal controls according to the recommendations of the International Society of Clinical Electrophysiology of Vision. The oscillatory potentials were extracted from the maximal combined response by high-pass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed with the expectation that this procedure may provide a new feature that could have some clinical significance. Timing delays occurred more frequently than amplitude reductions in the maximal combined response and flicker responses, while amplitude reductions were more common in the first and second oscillatory potentials. The hypernormal b-wave amplitude was rare. The summed amplitude of the oscillatory potentials was highly correlated with the total power of the oscillatory potentials (the frequency domain). A reduction of the second oscillatory potential amplitude was more common than a reduction of the summed amplitude or total power. The electroretinographic component that demonstrates retinal dysfunction in the earlier stage may be a valuable indicator. In the early stage, a delay in the a-wave time and a reduction in the second oscillatory potential amplitude were the most frequent abnormalities: analysis of variance demonstrated that the summed amplitude of the oscillatory potentials and second oscillatory potential amplitude and time were the most sensitive measures of the diabetic retina. Hence, the second oscillatory potential amplitude may be the most sensitive and valuable indicator representing a quantitative measure of overall retinal dysfunction.

Identification and expression of the Na+/H+ exchanger in mammalian cerebrovascular and choroidal tissues: characterization by amiloride-sensitive [3H]MIA binding and RT-PCR analysis

We report the initial characterization of [3H]5-(N-methyl-N-isobutyl)amiloride (MIA) binding to the Na+/H+ exchanger (NHE) and expression of its gene in mammalian cerebrovascular, choroidal and neocortical tissues. [3H]MIA bound reversibly to particulate fractions of rat, pig and human cerebral microvessels, choroid plexus and cerebral cortex. Scatchard analyses revealed binding to a single amiloride-sensitive site with dissociation constants (Kd) ranging from 20 to 90 nM for the various tissue preparations. The maximal binding capacities (Bmax) were between 2 to 17 pmol/mg protein and were several-fold greater in cerebral microvessels compared to the cerebral cortex. Amiloride, MIA, 5-(N, N-hexamethylene)amiloride (HMA), 5-(N, N-dimethyl)amiloride (DMA) and 5-(N-methyl-N-isopropyl)amiloride (IPA) variably displaced [3H]MIA binding to the microvessels in the following rank order: MIA>HMA>/=IPA>DMA>amiloride. Benzamil, a potent ligand of the Na+/Ca+ transporter was the least sensitive. These binding results were most compatible with the existence of the amiloride-sensitive NHE type 1 in the brain vascular and choroidal tissues. To substantiate this, we utilized reverse transcription polymerase chain reaction (RT-PCR) techniques to search for NHE-1 mRNA. Using primers corresponding to conserved sequences of the human growth factor-activatable NHE gene, RT-PCR revealed strong expression of NHE-1 mRNA in cerebral microvessels, choroid plexus, pial vessels and vascular smooth muscle cells relative to neocortical tissues from several species including rat, pig, cow, monkey and human subjects. Further confirmation of NHE-1 isoform mRNA expression in the cerebrovascular tissues was obtained by HpaII restriction digestion analysis and by subcloning and sequencing of the PCR amplified products. Our study suggests that mammalian cerebrovascular and choroidal tissues contain high amounts of the ubiquitous amiloride-sensitive [3H]MIA binding proteins consistent with the expression of NHE type 1 mRNA.

The amiloride-sensitive Na+/H+ exchange antiporter and control of intracellular pH in hippocampal brain slices

The intracellular pH, 7.54 +/- 0.03 (mean +/- S.D., n = 15), determined with the Neutral red method, of the hippocampal brain slice preparation under baseline incubation conditions is considerably more alkaline than the bath buffer pH. Neutralization by amiloride suggests that the alkalinity was due to Na+/H+ exchange antiporter activation. To characterize the brain Na+/H+ exchange antiporter we compared the inhibitory effects of MIA, amiloride and other 5-N substituted analogues on proton extrusion after acid loading by transient exposure to ammonium chloride in the isolated hippocampal brain slice preparation. The potencies of amiloride compounds on the initial recovery rate of intracellular pH after acid-loading were DMA > MIA > HMA = MHA > or = IPA-HCI > IPA > MNPA = Amil > Benzamil. The greater potency of the 5-N substituted analogs of amiloride over amiloride and benzamil strongly suggest that Na+/H+ exchange antiporter is the mechanism responsible for alkalinization in the isolated hippocampal brain slice in vitro.

Adenomyoepithelioma of the breast--its diagnostic problems and histogenesis

We report three cases of adenomyoepithelioma of the breast that occurred in middle aged women. The tumor is characterized by a balanced proliferation of epithelial tubules and surrounding myoepithelial cells that are spindle shaped or have clear cytoplasms. The first case mimicked tubular adenoma in the initial biopsy. However, on excision it turned out to be an adenomyoepithelioma of the tubular. The other two cases were lobulated types and had fibroadenomatous areas. The morphologic appearance of this tumor varies, making it misleading to other benign or even malignant lesions. The tumor has a potential for local recurrence, therefore, wide excision is recommended for proper diagnosis and treatment.

Sebaceous glands in the esophagus

We report a case of sebaceous glands in the esophagus diagnosed by endoscopic biopsy. The patient was a 47-year-old Korean man presented with postprandial pain of several months duration. An endoscopic examination disclosed an early gastric carcinoma in the gastric antrum and a 0.4 x 0.4 cm sized irregular lobulated nodule in the middle esophagus. Microscopically, the lobule was proven to be sebaceous glands in the submucosa. Possible histogenesis of this lesion is discussed.

Intracranial immature teratoma with syncytiotrophoblasts and tumor marker positive intestinal lining cells

Intracranial teratomas are rare entities that can present as a pure type or as mixed germ cell tumor. Cases of mixed germ cell tumor composed of immature teratoma and choriocarcinoma have been reported. Also, immature teratoma can be mixed with only syncytiotrophoblasts. We report a case of immature teratoma with syncytiotrophoblasts of the brain discovered in a 3-year-old male baby. Serum human chorionic gonadotrophin (hCG) was normal and serum alpha-fetoprotein (AFP) was elevated. The tumor was mainly composed of intestinal glands, and neither endodermal sinus tumor nor embryonal carcinomatous elements were found. The cells lining the intestinal glands were positive for hCG and AFP. These findings suggest that the syncytiotrophoblasts are differentiated from the endoderm and AFP is not necessarily a marker exclusive to endodermal sinus tumor or embryonal carcinoma.

The nitrosation of hexetidine and hexedine: characterization of the major nitrosamine from common antimicrobial agents

The acidic nitrosation of hexetidine and hexedine, common antimicrobial agents and drug constituents, leads to a mixture of nitrosamines. The major nitrosamine product, "HEXNO", forms rapidly in yields as high as 60% over the pH range 1-4.8 at incubation times of 1 h at 37 degrees C with 40 mM NO2- and 10 mM hexetidine. On the basis of extensive spectroscopic characterization and independent synthesis HEXNO has been assigned the structure of 1-(2-ethylhexyl)-3-nitroso-4-methyl-4-[[N-(2-ethylhexyl)-N- nitrosoamino]methyl]imidazolidine (7). The synthesis of HEXNO involves the novel interception by potassium nitrite in ether/18-crown-6 of an imminium ion produced from the reaction of hexedine with benzyl chloroformate. Collapse of the alpha-amino nitrous ester produced by this reaction yields the nitrosamine containing carbamate 8, which yields HEXNO after removal of the carbamate with trimethylsilyl iodide and subsequent nitrosation. The rapid formation of HEXNO from hexetidine and hexedine supports the hypothesis that tertiary geminal diamines will produce nitrosamines rapidly by a mechanism which involves the cleavage of a nitrosammonium ion with the assistance of the neighboring nitrogen atom. This process is deemed to be of possible importance in the endogenous production of potentially carcinogenic nitrosamines because of its low nitrite requirement and high nitrosation rate. The available data suggest the probable formation of HEXNO and other nitrosamines from hexetidine under conditions of its use.

An aziridinium ion intermediate in the nitrosation of a hexetidine model

The nitrosation chemistry of 1,3,5-trimethyl-5-aminohexahydropyrimidine (2) has been investigated as a model for the behavior of the antimicrobial agent hexetidine (1) under similar conditions. The reaction of 2 with sodium nitrite in glacial acetic acid gives 4-methyl-4-[(methylnitrosamino)methyl]-3-nitroso-1,3-oxazolidine (4) as the major nitrosamine. This compound arises from a molecular rearrangement which proceeds through the diazotization of the primary amino group followed by intramolecular displacement of nitrogen to generate an aziridinium ion. The N-nitrosooxazolidine 4 forms from the nitrosation of an imidazolidine produced from the aziridinium ring hydrolytic opening. The N-nitrosooxazolidine 4, an isomer, 5-methyl-5-[(methylnitrosamino)methyl]-3-nitroso-1,3-oxazolidine (14), which is not formed in the nitrosation of 2, and an analog 4-methyl-4-[[(2-ethylhexyl)nitrosamino]methyl]-3-nitroso-1,3-oxazolidine (22) have been independently synthesized. The N-nitrosooxazolidine 22 which would be formed from hexetidine is not present in its nitrosation mixture, suggesting the absence of reactive aziridinium ions in that case. The dissimilar nitrosation chemistry of 2 and 1 are discussed.