Pathogens In Bloodstream Infections Research Articles

Epidemiology of Posttransrectal Prostate Biopsy Bloodstream Infections and Impact of a Screening Program

Background: Antibiotic prophylaxis choice for transrectal prostate biopsy (TRPB) has been affected by the emergence of fluoroquinolone-resistant Escherichia coli (FQRE). Prebiopsy FQRE screening and targeted antibiotic prophylaxis may reduce post-TRPB bloodstream infection (BSI). We assessed the impact of a FQRE screening program on post-TRPB BSIs at an academic medical center. Methods: We implemented a FQRE screening program and targeted TRPB antimicrobial prophylaxis guidelines on May 1, 2017 (Fig. 1). We performed a retrospective cohort study of all TRPB and compared the incidence of post-TRPB BSI (within 7 calendar days) per 100 procedures before the intervention (January, 1, 2016, to April 30, 2017) and to the incidence after the intervention (May 1, 2017, to August 31, 2019). We used a subanalysis to compare BSI incidence between patients with positive (+) and negative () FQRE screens and appropriate prophylaxis use, defined as administration of guideline-recommended antibiotics. The Fisher exact test of independence was used to analyze nominal data. Results: The analysis included 2,157 TRPB procedures: 647 in the preintervention period and 1,510 in the postintervention period. FQRE screening compliance was 61% (n = 914) in the postintervention group (Fig. 2); 168 FQRE screens (18%) were positive. The median time from FQRE screen to procedure was 40 days (IQR, 13–69). Postprocedure BSI rates were higher in than those in the preimplementation group; however, this difference was not statistically significant (0.86 vs 0.46; OR, 2.01; P = .42). Among FQRE-screened patients, BSI rates differed significantly between FQRE+ and FQRE patients (2.98 vs 0.54; OR, 5.67; 95% CI, 1.21–28.94; P = .01). Screened patients receiving appropriate prophylaxis had lower BSI rates than those receiving inappropriate prophylaxis; however, this was not statistically significant (1.10 vs 2.02; OR, 0.54; P = .35). The most common BSI pathogen was E. coli (2 (67%) before implementation and 10 (77%) after implementation). Also, 5 E. coli BSIs (50%) were fluoroquinolone resistant in the postimplementation group compared to 1 (33%) in the preimplementation group. Of 13 postimplementation BSIs, 6 occurred in patients who received aminoglycosides perioperatively; however, all 6 BSI pathogens were aminoglycoside sensitive. Conclusions: Compliance with our FQRE screening program and antimicrobial prophylaxis protocol was moderate. Although pre- and postimplementation differences in BSI rates were not statistically significant, the high failure rate among patients receiving aminoglycosides was concerning and led to a change in TRPB prophylaxis guidelines. Reasons for increased BSI risk among FQRE+ patients may include prophylaxis agent, dose, timing, or other confounding factors associated with drug-resistant pathogens. Facilities implementing FQRE screening protocols should evaluate the efficacy of their program and periodically review screening compliance, prophylaxis dosing and timing adherence, and impact on patient-level outcomes.Funding: NoneDisclosures: None

The impact of delayed analysis of positive blood cultures on the performance of short-term culture followed by MALDI-TOF MS

BackgroundShort-term culture followed by MALDI-TOF MS is one of the most widely used methods for fast identification of microorganisms from blood cultures. The method identifies the vast majority of bloodstream infection pathogens in 2–6 h after positive blood culture. Transport time of blood culture bottles to laboratories is a major problem affecting total turnaround time. Therefore, many central laboratories establish satellite blood culture systems in other clinics and hospitals to allow blood culture bottles to be incubated immediately after sampling. However, positive blood culture bottles still need to be transported to the clinical microbiology laboratory for analysis. The aim of this study was to investigate how delayed analysis of positive blood culture bottles would affect the short-term culture followed by MALDI-TOF MS method. Materials/methodsTo simulate the effect of transportation and delayed analysis of blood culture bottles, 51 simulated blood culture bottles were incubated for 0, 2, 4 and 24 h at room temperature. After each time interval, a 2 to 4 h short-term culture followed by MALDI-TOF MS was performed. In addition, 257 prospective clinical positive blood culture bottles were analysed with the same method after a 24 h incubation at room temperature. ResultsIn simulated samples, all (120/120) Gram-negative bacteria and 77/84 (91.6%) Gram-positive bacteria were accurately identified at species-level after a 2 h short-term culture, regardless of the duration of simulated transport time. In the clinical samples, 100/116 (86.2%) Gram-negative, and 44/141 (31.2%) Gram-positive bacteria were accurately identified at species-level after a 2 h short-term culture. After contaminants were excluded, 39/71 (54.9%) Gram-positive bacteria could be identified after 2 h. After a 4 h short-term culture, 112/116 (96.6%) Gram-negative, and 108/141 (76.6%) Gram-positive bacteria were accurately identified at species-level. Of the clinically relevant Gram-positive bacteria, 68/71 (95.8%) were identified at species-level after 4 h. ConclusionsShort-term culture followed by MALDI-TOF MS can provide fast and accurate results for identification of clinically relevant bacteria, despite long transportation times from satellite laboratories. The present data shows that the method can be used for identification of microorganisms from positive blood cultures transported from satellite blood culture systems.

EUCAST rapid antimicrobial susceptibility testing (RAST) in blood cultures: validation in 55 European laboratories.

ObjectivesWhen bloodstream infections are caused by resistant bacteria, rapid antimicrobial susceptibility testing (RAST) is important for adjustment of therapy. The EUCAST RAST method, directly from positive blood cultures, was validated in a multi-laboratory study in Europe.MethodsRAST was performed in 40 laboratories in northern Europe (NE) and 15 in southern Europe (SE) from clinical blood cultures positive for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Categorical results at 4, 6 and 8 h of incubation were compared with results for EUCAST standard 16–20 h disc diffusion. The method, preliminary breakpoints and the performance of the laboratories were evaluated.ResultsThe total number of isolates was 833/318 in NE/SE. The number of zone diameters that could be read (88%, 96% and 99%) and interpreted (70%, 81% and 85%) increased with incubation time (4, 6 and 8 h). The categorical agreement was acceptable, with total error rates in NE/SE of 2.4%/4.9% at 4 h, 1.1%/3.5% at 6 h and 1.1%/3.3% at 8 h. False susceptibility at 4, 6 and 8 h of incubation was below 0.3% and 1.1% in NE and SE, respectively, and the corresponding percentages for false resistance were below 1.9% and 2.8%. After fine-tuning breakpoints, more zones could be interpreted (73%, 89% and 93%), with only marginally affected error rates.ConclusionsThe EUCAST RAST method can be implemented in routine laboratories without major investments. It provides reliable antimicrobial susceptibility testing results for relevant bloodstream infection pathogens after 4–6 h of incubation.

A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in adult patients with hematological disease during the period 2014-2018

目的探讨2014–2018年成人血液病患者发生血流感染的病原菌分布和耐药情况，为该类患者合理使用抗菌药物提供数据参考。方法回顾性分析2014年1月至2018年12月中国医学科学院血液病医院收治的血液病合并血流感染患者的临床资料、病原菌种类分布和药物敏感性数据。结果5年内共1 478例血液病患者发生1 935次血流感染，1 700例次（87.9%）发生在中性粒细胞缺乏期，14 d与30 d全因死亡率分别为5.5%和8.2%。52.7%的血流感染存在伴随症状，主要为呼吸道症状、肛周黏膜损伤及消化道症状，比例分别为12.4%、12.3%和9.1%。共分离出2 025株病原菌，革兰阴性菌1 551株（76.6%），主要为大肠埃希菌、肺炎克雷伯菌和铜绿假单胞菌；革兰阳性球菌423株（20.9%），主要为葡萄球菌属与草绿色链球菌；真菌51株（2.5%），以热带念珠菌为主。肠杆菌科细菌对哌拉西林/他唑巴坦、碳青霉烯类、阿米卡星耐药率<10%。其中肺炎克雷伯菌对头孢吡肟、哌拉西林/他唑巴坦、美罗培南耐药率呈逐年上升趋势。铜绿假单胞菌对哌拉西林/他唑巴坦、喹诺酮类、氨基糖苷类抗菌药物耐药率<5%，低于碳青霉烯类。共检出耐甲氧西林金黄色葡萄球菌11株，耐万古霉素肠球菌1株。结论成人血液病患者血流感染病原菌分布广泛，不同菌种耐药率差异较大，且部分菌种耐药呈上升趋势，应根据不同人群血流感染病原菌分布及耐药情况合理使用抗菌药物。

Improving Oral Health and Modulating the Oral Microbiome to Reduce Bloodstream Infections from Oral Organisms in Pediatric and Young Adult Hematopoietic Stem Cell Transplantation Recipients: A Randomized Controlled Trial.

Bloodstream infections (BSIs) from oral organisms are a significant cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients. There are no proven strategies to decrease BSIs from oral organisms. The aim of this study was to evaluate the impact of daily xylitol wipes in improving oral health, decreasing BSI from oral organisms, and modulating the oral microbiome in pediatric HSCT recipients. This was a single-center 1:1 randomized controlled trial in pediatric HSCT recipients age >2 years. Age-matched healthy children were enrolled to compare the oral microbiome. The oral hygiene standard of care (SOC) group continued to receive the standard oral hygiene regimen. The xylitol group received daily oral xylitol wipes (with .7 g xylitol) in addition to the SOC. The intervention started from the beginning of the transplantation chemotherapy regimen and extended to 28 days following transplantation. The primary outcome was oral health at interval time points, and secondary outcomes included BSIs from oral organisms in the first 30 days following transplantation, oral microbiome abundance, and diversity and oral pathogenic organism abundance. The study was closed early due to efficacy after an interim analysis of the first 30 HSCT recipients was performed (SOC group, n=16; xylitol group, n=14). The xylitol group had a significantly lower rate of gingivitis at days 7, 14, and 28 following transplantation (P=.031, .0039, and .0005, respectively); oral plaque at days 7 and 14 (P=.045 and .0023, respectively); and oral ulcers >10 mm at day 14 (P=.049) compared with the SOC group. The xylitol group had no BSI from oral organisms compared with the SOC group, which had 4 (P=.04). The xylitol group had significantly lower abundance of potential BSI pathogens, such as Staphylococcus aureus (P=.036), Klebsiella pneumoniae (P=.033), and Streptococcus spp (P=.011) at the day after transplantation compared with the SOC group. Healthy children and young adults had significantly increased oral microbiome diversity compared with all HSCT recipients (P < .001). The addition of xylitol to standard oral care significantly improves oral health, decreases BSI from oral organisms, and decreases the abundance of pathogenic oral organisms in pediatric and young adult HSCT recipients.

Hemocompatible magnetic particles with broad-spectrum bacteria capture capability for blood purification

Pathogen capture and removal from whole blood is a new strategy for extracorporeal blood purification, especially in initial treatment of sepsis before pathogen identification. Herein, hemocompatible magnetic particles with broad-spectrum bacteria capture capability were proposed for pathogen removal from whole blood, omitting the necessity of pathogen identification. Firstly, we designed and synthesized a new kind of imidazolium-based ionic liquid with good antibacterial activity, and polydopamine coating was utilized as a hemocompatible platform to immobilize ionic liquids on Fe3O4 nanoparticles, forming the hemocompatible magnetic particles (Fe3O4@PDA-IL). The magnetic particles exhibited good hemocompatibility and performed well in the removal of various species of clinically significant pathogens from human whole blood, including S. aureus, E. coli, and the hard-to-treat bacteria of P. aeruginosa and Methicillin-resistant S. aureus, which are the most common pathogens in bloodstream infections. Besides, the Fe3O4@PDA-IL particles were also capable to remove bacterial endotoxins from blood, inhibiting further aggravation of sepsis. Overall, we demonstrated the application of hemocompatible magnetic particles in the removal of pathogens and bacterial endotoxins from whole blood via electrostatic and hydrophobic interactions, without significant effects on blood cells or the activation of coagulation and complement, addressing the feasibility of using imidazolium-based ionic liquids for bacteria capture and removal from whole blood. It would contribute to the development of magnetic separation-based approaches to remove bacteria and bacterial endotoxin for extracorporeal blood purification, especially in initial sepsis therapy before pathogen identification.

Antimicrobial Resistance Pattern of Nosocomial Infections at a Referral Teaching Hospital

Background: The choice of appropriate antibiotics to treat nosocomial infections requires knowledge of antibiotic resistance pattern in the hospitals. The aim of this study was to determine antimicrobial resistance patterns of common pathogens of nosocomial infections (pneumonia, UTI, bloodstream infection, wound infection) in a referral teaching hospital. Methods: This cross-sectional study was conducted over a 6-month period. The pathogens isolated from biological samples of hospitalized patients with nosocomial pneumonia, UTI, bloodstream infection, or wound infection underwent antibiotic susceptibility testing by Kirby-Bauer method (disk diffusion test). Results: Over the study period, 442 cases of infection were recorded. Pneumonia (n = 204, 46.2%) and UTI (n = 118, 26.7%) showed the most frequency followed by BSI (n = 71, 16.1%) and wound infection (n = 49, 11%). Acinetobacter baumannii was the most common pathogen of nosocomial pneumonia infection that showed the most susceptibility to colistin (100%). Escherichia coli, the most common pathogen of urinary tract infections, showed the highest sensitivity to colistin (100%). Staphylococcus epidermidis was the most common bloodstream infection pathogen that showed the most sensitivity to vancomycin (100%). Enterococcus spp., the most common pathogens of wound infection, had the most susceptibility to linezolid (100%). Conclusion: Nosocomial infections in our hospital have high rate of resistance to antibiotics representing the importance of improvement in antibiotic use and infection control. J Pharm Care 2020; 8(1): 26-34.

Prevalence, co-infection and antibiotic resistance of Escherichia Coli from blood and urine samples at a hospital in Jamaica.

Escherichia coli (E. coli) is a very common uro-pathogen and pathogen of bloodstream infections (BSI) in Jamaica. The aim of this study was to examine this organism's prevalence, determine co-infection rates and assess antibiotic resistance patterns. In the absence of automated systems, data on all E. coli isolates identified at the University Hospital of the West Indies in Kingston, Jamaica during the first six months of 2008 and 2012 was collected and sorted. Data were analyzed using IBM SPSS Statistics version 20 for Windows. A total of 1188 isolates (1072 from urine and 116 from blood) was analyzed. Patients with E. coli BSI were older than those with E. coli urinary tract infections (UTI) (55.3 years vs 42.4 years, p < 0.05) and both had a female predominance. Sensitivity profiles in 2012 for E. coli in blood and urine were highest for the carbapenems, Amikacin and Nitrofurantoin and lowest for the fluoroquinolones and Trimethoprim-sulfamethoxazole. Based on antimicrobial susceptibility patterns, Nitrofurantoin was identified as an appropriate choice for empiric therapy for UTI. Ten antibiotics were noted in this study to have developed statistically significant antibiotic resistance. Patients with E. coli BSI had a co-infection E. coli UTI rate of 39%. Resistance patterns change drastically in a few years making frequent antimicrobial susceptibility profiling necessary. Further studies would be beneficial in guiding management of these patients.

Applicability of an in-house saponin-based extraction method in Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identifying bacterial and fungal species in positively flagged pediatric VersaTREK blood cultures

Early identification of pathogens causing bloodstream infection (BSI) is critical for prompt administration of appropriate antimicrobial therapy. We used an in-house saponin-based extraction method to evaluate the performance of Bruker Biotyper MALDI-TOF MS system (MALDI Biotyper) for bacterial and fungal identification in 2013 positively-flagged VersaTREK blood culture bottles. A total of 180 monomicrobial and 23 polymicrobial positive blood cultures were investigated. Among monomicrobial positive blood cultures, the MALDI Biotyper recognized 90.6% and 81.7% of organisms directly from the flagged blood culture bottles to the genus and species levels, respectively. The MALDI Biotyper also correctly characterized one of the polymicrobial organisms to the species level in 20 (87%) bottles and to the genus level in 21 (91.3%) bottles. The overall identification rate using our protocol was 90.6% (184/203) and 82.3% (167/203) for genus and species levels, respectively. Identification accuracy was higher for Gram-positive than Gram-negative organisms and was the lowest for yeasts. Score values of identification were ≥1.500 for 200 (98.5%) bottles, ≥1.700 for 195 (96.1%) bottles and ≥2.000 for 182 (89.7%) bottles. Moreover, 83.5% and 92% of the isolates were identified precisely to species and genus level with the lower cutoff score of 1.500. Using our protocol also helped identifying BSI pathogens 18-24h earlier compared to the sub-cultured colonies. Using Bruker MALDI Biotyper for identification of isolates directly from positive VersaTREK blood culture bottles, our in-house saponin-based protocol provided a more rapid turn-around time for correct identification of BSI pathogens than the conventional methods.

Evaluation of two rapid molecular test systems to establish an algorithm for fast identification of bacterial pathogens from positive blood cultures

Fast identification of pathogens directly from positive blood cultures is of highest importance to supply an adequate therapy of bloodstream infections (BSI). There are several platforms providing molecular-based identification, detection of antimicrobial resistance genes, or even a full antimicrobial susceptibility testing (AST). Two of such test systems allowing rapid diagnostics were assessed in this study: The Biofire FilmArray® and the Genmark ePlex®, both fully automated test system with a minimum of hands-on time. Overall 137 BSI episodes were included in our study and compared to conventional culture–based reference methods. The FilmArray® is using one catridge including a panel for the most common bacterial and fungal BSI pathogens as well as selected resistance markers. The ePlex® offers three different cartridges for detection of Gram-positives, Gram-negatives, and fungi resulting in a broader panel including also rare pathogens, putative contaminants, and more genetic resistance markers. The FilmArray® and ePlex® were evaluated for all 137 BSI episodes with FilmArray® detecting 119 and ePlex® detecting 128 of these. For targets on the respective panel of the system, the FilmArray® generated a sensitivity of 98.9% with 100% specificity on Gram-positive isolates. The ePlex® system generated a sensitivity of 94.7% and a specificity of 90.7% on Gram-positive isolates. In each case, the two systems performed with 100% sensitivity and specificity for the detection of Gram-negative specimens covered by each panel. In summary, both evaluated test systems showed a satisfying overall performance for fast pathogen identification and are beneficial tools for accelerating blood culture diagnostics of sepsis patients.

The EUCAST rapid disc diffusion method for antimicrobial susceptibility testing directly from positive blood culture bottles.

ObjectivesWith increasing antimicrobial resistance, rapid antimicrobial susceptibility testing (RAST) becomes important, especially in patients with bloodstream infections. EUCAST decided to develop a standardized rapid method, based on EUCAST disc diffusion, to offer susceptibility reports within 4–8 h of a positive blood culture (BC).MethodsBC bottles were spiked with clinical isolates (n = 332) of the seven most relevant sepsis pathogens with a variety of resistance mechanisms. RAST was performed directly from the bottle and zones read after 4, 6 and 8 h. Several variables were investigated, including the effect of using different BC bottles and of a 0–18 h delay between a positive signal and the performance of RAST.ResultsFor five species, most inhibition zones could be read after 4 h. The proportion of results that could be interpreted increased from 75% at 4 h to 84% after 8 h. Categorical agreement against the reference method was good, with error rates of false susceptibility of 0.2%, 0.2% and 0.2% at 4, 6 and 8 h and false resistance of 1.2%, 0.2% and 0.1% at 4, 6 and 8 h, respectively.ConclusionsWith the EUCAST RAST method, reliable AST results can be delivered within 4–8 h of positivity of BC bottles for seven important bloodstream infection pathogens. To reduce the occurrence of errors and to absorb the variability caused by using a non-standardized inoculum, material from different manufacturers and workflow-related delays, we have introduced an area in which interpretation is not permitted, the Area of Technical Uncertainty.

Hospital-wide ELectronic medical record evaluated computerised decision support system to improve outcomes of Patients with staphylococcal bloodstream infection (HELP): study protocol for a multicentre stepped-wedge cluster randomised trial

IntroductionStaphylococci are the most commonly identified pathogens in bloodstream infections. Identification of Staphylococcus aureus in blood culture (SAB) requires a prompt and adequate clinical management. The detection of coagulase-negative staphylococci...

Performance of a new Candida anti-mannan IgM and IgG assays in the diagnosis of candidemia.

ABSTRACT Candida is one of the most frequent pathogens of bloodstream infections, which is associated with high morbidity and mortality rates. Rapid immunological detection methods are essential in the early diagnosis of candidemia. Anti-mannan is one of host-derived biomarkers against cell wall components of Candida. We conducted this study to evaluate the diagnostic performance of two anti-mannan assays (IgM, IgG) for candidemia through the analysis of 40 candidemia patients, 48 participants with Candida colonization and 213 participants with neither Candida colonization nor Candida infections (13 patients with other bloodstream infections, 145 hospitalized patients and 55 healthy controls). The performance of the two assays were evaluated by calculating their sensitivity and specificity. The sensitivity ranged from 0.78 to 0.80 for the IgM assay and 0.68 to 0.75 for the IgG assay. The specificity ranged from 0.97 to 0.98 for the IgM assay and 0.91 to 0.94 for the IgG assay. The diagnostic performance of the anti-mannan IgM assay was better than that of IgG, with higher sensitivity and specificity. Combining the two assays (positive results of single or both assays are both considered as positive) could improve the sensitivity up to 0.93 (0.79-0.98) and only slightly reduce the specificity (0.93(0.89-0.95)). The anti-mannan IgM, IgG assays are rapid and cost-effective assays that may be probably useful in the diagnosis of candidemia.

ESKAPE Pathogens in Bloodstream Infections Are Associated With Higher Cost and Mortality but Can Be Predicted Using Diagnoses Upon Admission.

BackgroundESKAPE bacteria are thought to be especially resistant to antibiotics, and their resistance and prevalence in bloodstream infections are rising. Large studies are needed to better characterize the clinical impact of these bacteria and to develop algorithms that alert clinicians when patients are at high risk of an ESKAPE infection.MethodsFrom a US data set of >1.1 M patient encounters, we evaluated if ESKAPE pathogens produced worse outcomes than non-ESKAPE pathogens and if an ESKAPE infection could be predicted using simple word group algorithms built from decision trees.ResultsWe found that ESKAPE pathogens represented 42.2% of species isolated from bloodstream infections and, compared with non-ESKAPE pathogens, were associated with a 3.3-day increase in length of stay, a $5500 increase in cost of care, and a 2.1% absolute increase in mortality (P < 1e-99). ESKAPE pathogens were not universally more resistant to antibiotics, but only to select antibiotics (P < 5e-6), particularly against common empiric therapies. In addition, simple word group algorithms predicted ESKAPE pathogens with a positive predictive value of 7.9% to 56.2%, exceeding 4.8% by random guessing (P < 1e-99).ConclusionsTaken together, these data highlight the pathogenicity of ESKAPE bacteria, potential mechanisms of their pathogenicity, and the potential to predict ESKAPE infections upon admission. Implementing word group algorithms could enable earlier and targeted therapies against ESKAPE bacteria and thus reduce their burden on the health care system.

Development of a Multiplex PCR Platform for the Rapid Detection of Bacteria, Antibiotic Resistance, and Candida in Human Blood Samples.

The diagnosis of bloodstream infections (BSIs) still relies on blood culture (BC), but low turnaround times may hinder the early initiation of an appropriate antimicrobial therapy, thus increasing the risk of infection-related death. We describe a direct and rapid multiplex PCR-based assay capable of detecting and identifying 16 bacterial and four Candida species, as well as three antibiotic-resistance determinants, in uncultured samples. Using whole-blood samples spiked with microorganisms at low densities, we found that the MicrobScan assay had a mean limit of detection of 15.1 ± 3.3 CFU of bacteria/Candida per ml of blood. When applied to positive BC samples, the assay allowed the sensitive and specific detection of BSI pathogens, including blaKPC-, mecA-, or vanA/vanB-positive bacteria. We evaluated the assay using prospectively collected blood samples from patients with suspected BSI. The sensitivity and specificity were 86.4 and 97.0%, respectively, among patients with positive BCs for the microorganisms targeted by the assay or patients fulfilling the criteria for infection. The mean times to positive or negative assay results were 5.3 ± 0.2 and 5.1 ± 0.1 h, respectively. Fifteen of 20 patients with MicrobScan assay-positive/BC-negative samples were receiving antimicrobial therapy. In conclusion, the MicrobScan assay is well suited to complement current diagnostic methods for BSIs.

Contribution of specific pathogens to bloodstream infection mortality in neutropenic patients with hematologic malignancies: Results from a multicentric surveillance cohort study.

Bloodstream infection (BSI) remains a serious complication in patients with hematologic malignancies and neutropenia. The risk factors for mortality after BSI and the contributions of BSI pathogens to mortality remain incompletely understood. We evaluated first BSI among adult neutropenic patients undergoing high-dose chemotherapy for hematologic malignancies in the setting of (a) an early disease stage of autologous (auto-HSCT) or allogeneic (allo-HSCT) hematopoietic stem cell transplantation or (b) for acute leukemia. Risk factors for intensive care admission and all-cause mortality were analyzed by multivariable logistic regression 7 and 30days after onset of the first BSI in the first neutropenic episode. Between 2002 and 2015, 9080 patients met the study inclusion criteria, and 1424 (16%) developed BSIs, most of them during the first week of neutropenia. Mortality during neutropenia within 7days and 30days after BSI onset was 2.5% and 5.1%, respectively, and differed considerably between BSI pathogens. Both 7-day and 30-day mortalities were highest for Pseudomonas aeruginosa BSI (16.7% and 26.7%, respectively) and lowest for BSI due to coagulase-negative Staphylococcus spp. (CoNS) and Streptococcus spp. BSI pathogens were independently associated with 7-day mortality included Paeruginosa, Klebsiella spp., Enterobacter spp., Serratia spp., and enterococci. Only gram-negative BSI and candidemia were associated with admission to intensive care within 7days after BSI onset. BSI caused by Paeruginosa continues to carry a particularly poor prognosis in neutropenic patients. The unexpected association between enterococcal BSI and increased mortality needs further study.

MRSA contamination in ambulances: a systematic review

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug resistant organism (MDRO) frequently involved in skin, soft tissue and bone infections. Moreover, it is one of the most frequently isolated pathogen in bloodstream infections in European countries. Because of its capacity to survive on inanimate surfaces, this microorganism could be detected not only on hospital environment, but also in other healthcare settings such as ambulances. We performed a systematic review in order to study the level of MRSA contamination in ambulances (vehicle surfaces and medical equipment). Methods In March 2019 we searched studies in PubMed using the key search terms “MRSA, ambulance”. We included different designs of studies in English. Results The research yielded 18 publications: after title, abstract and full text’s analysis, 9 manuscripts were included in this review. Studies were conducted from 2007 to 2018 in USA, Egypt, Poland, Germany and South Korea. Overall, the number of ambulances sampled for MRSA was 511 (min. 3-max. 150), and 64 (12.5%) resulted contaminated by MRSA. Sampling points examined for each vehicle varied from 5 to 33, for a total of 5872 (min. 39-max. 2136) samplings performed. The amount of MRSA positive samplings was 145/5872 (2.5%) (min. 1-max. 43). Stretcher resulted the most frequently contaminated fomite (29 of the 145 MRSA positive samplings, 20%). Conclusions Despite MRSA prevalence is decreasing in Europe, recent studies showed how this MDRO could still be responsible of a remarkable burden in terms of attributable deaths and costs. Implementing effective sanitation procedures with a continuative monitoring of the processes is highly recommended in all the healthcare settings, including ambulances. Automated terminal disinfection of these vehicles, adopting technologies such as ultraviolet germicidal irradiation or hydrogen peroxide aerosol, could reduce bacterial contamination hosted on surfaces and medical equipment. Key messages Although the percentage of isolates of MRSA in European countries is decreasing, the burden this multidrug resistant organism in terms of mortality and costs remains remarkable. Ambulances must be considered as a potential reservoir of MRSA because of its ability to survive on inanimate surfaces, and adequate sanitation procedures should be frequently performed.

192. Augmenting Utility of Rapid Diagnostic Testing in Treatment of Gram-Negative Bacteremia with Stewardship Intervention

BackgroundRapid diagnostic tests (RDT) can identify pathogens in bloodstream infections (BSI) in less than 24 hours. Our institution utilizes an RDT for blood cultures (BCx) that can detect various organisms and resistance determinants. A retrospective evaluation conducted in our institution calculated the negative predictive values (NPV) of various Gram-negative pathogens and susceptibility to target antimicrobials in the absence of detected resistance markers. Resultant NPV >90% for E. coli and K. pneumoniae to ceftriaxone support use of RDT with stewardship intervention for more rapid de-escalation of antimicrobial therapy in patients with resistance marker-negative BSI.MethodsIn our facility, all positive BCx are processed through RDT. In the post-intervention group, pharmacists monitored RDT results and provided recommendations. Our IRB-approved, prospective study assessed time to antimicrobial de-escalation in treatment of resistance marker-negative E. coli and K. pneumoniae BSI before (January 1 to December 31, 2018) and after Stewardship intervention (January 1 to March 31, 2019). Secondary outcomes included days of therapy (DOT) of target narrow-spectrum β-lactams, carbapenems, and non-carbapenem anti-pseudomonal (NCAP) β-lactams, length of stay (LOS), and treatment failure. Data were analyzed using the Fisher exact or Chi-square and t-test for categorical and continuous data, respectively.ResultsOf the 12,893 evaluated RDT results in the pre-intervention group and 2,238 post intervention, 41 and 12 patients met inclusion criteria, respectively. Baseline characteristics were similar in both groups. Time to de-escalation to a target agent was decreased by 24 hours after stewardship intervention (50 v 74.6 hours) (P = 0.14). There were no statistically significant differences in DOTs for target agents (5.19 v 5.25 DOT; P = 0.48), carbapenems (1.29 v 1.08 DOT; P = 0.41), or NCAP β-lactams (1.73 v 2.33; P = 0.25). Treatment failure (2 in each group; P = 0.17) and LOS (10.9 v 11.9 days; P = 0.4) were similar between groups. Protocol compliance and intervention acceptance rate was approximately 60%.ConclusionAppreciation of NPVs and utilization of stewardship intervention allowed for early de-escalation of empiric therapy in patients with resistance marker-negative E. coli and K. pneumoniae bacteremia. Disclosures All authors: No reported disclosures.

226. Nine-year Survey of Bloodstream Infections (BSIs) across Six Types of Solid-organ Transplant (SOT) at a Large University Medical Center

BackgroundBSIs are common in SOT patients. We surveyed BSIs across 6 types of SOT over 9 years at our center.MethodsWe conducted a retrospective study of BSI among patients transplanted from January 2010 to January 2019. Single blood cultures positive for coagulase-negative staphylococci, Corynebacterium, Bacillus, or Propionibacterium were excluded.Results3,358 patients underwent SOT, including kidney (K, 43%, 1432), lung (Lu, 23%, 778), liver (Li, 21%, 700), heart (H, 8%, 256), pancreas (P, 4%, 149), and small bowel/multivisceral (SB/MV 1%, 43). 16% (529) of patients had ≥1 episode of BSI. There were 770 BSIs; 14% (105/770) were recurrent. Median number of BSI was 1/patient (range: 1 to 7). BSI rates were highest among SB/MV patients (53%), followed by Lu (22%), Li (20%), P (15%), H (14%) and K patients (14%) (Figure 1). 20% (156), 24% (187) and 7% (52) of BSI occurred at ≤30 d, 31–180 d, and 181–365 d after SOT, respectively. BSI rates at ≤ and >180 d post-SOT were 3.6 and 0.65/1000 pt-d, respectively (P < 0.0001). Most common bacteria were Enterobacteriaceae (35%) and Enterococcus spp. (22%). Candida spp. accounted for 6% (49/770) of BSIs. Enterobactericeae were most common among intra-abdominal SOT patients, whereas Enterococcus and non-fermenting Gram-negatives were most common in Lu patients (Figure 2). 8% (65) of BSI was polymicrobial. From 2016 to 2018, 15% (14/96) of Enterobacteriaceae BSIs were multi-drug-resistant (MDR); 8% (8/96) were extensively drug resistant (XDR). 23% (3/13) of P. aeruginosa were MDR (all XDR). 70% (14/20) and 5% (1/20) of E. faecium and E. faecalis were vancomycin-resistant, respectively. Thirty-day mortality following BSI diagnosis was highest for H (31%), followed by Lu (15%), Li (10%), P (9%) and SB/MV (4%) patients. Patients with bacteremia had higher mortality than patients with no bacteremia (Figure 3).ConclusionBSIs are common after SOT, and associated with significant short- and long-term mortality. Almost half of BSIs occur within the first 6 months of SOT, when BSI rates are significantly higher than at later time points. Predominant BSI pathogens differ between SOT types; as such, empiric antimicrobial therapy decisions should be organ-specific. At our center, MDR and XDR Gram-negative bacteria and VRE are common; centers should use overall SOT and organ-specific antibiograms to drive empiric antimicrobial strategies. Disclosures All authors: No reported disclosures.

Invasive Fungal Infections in the Pediatric Intensive Care Unit.

Invasive Fungal Infections in the Pediatric Intensive Care Unit.