Cases Of Bloodstream Infection Research Articles

Bloodstream Infections with Opportunistic Pathogens in COVID-19 Era: A Real Challenge Necessitates Stringent Infection Control.

Background : Bloodstream infections (BSI) due to opportunistic microbes in the coronavirus disease 2019 (COVID-19) pandemic lead to high morbidity and mortality among hospitalized patients. Thus, it is vital to find out the risk factors of BSI and to learn the ways to mitigate it. Aim : The aim of this study was to evaluate important risk factors of BSI due to opportunistic pathogens and to assess the role of the rigid infection control program to deal with this issue. Methods : A prospective, cross-sectional study was performed for 6 months on 150 patients admitted in both COVID-19 and non-COVID-19 intensive care units of our hospital. BSI was confirmed by the BACTEC and Vitek 2 compact system. Prospective surveillance and environmental sampling were carried out for source tracking along with rigorous infection control measures and the outcome was analyzed. Findings : Burkholderia cepacia, Elizabethkingia meningoseptica, Candida auris, vancomycin-resistant Enterococcus , and Achromobacter xylosoxidans were the common opportunistic pathogens isolated from a single or paired blood sample(s) in our study. Key risk factors were prolonged intensive care unit stay, central venous access, mechanical ventilation, immune-compromised condition, and use of biologics. Reverse osmosis water and used normal saline bottles were the common environmental source of infection. Following the implementation of precise infection control measures, there was a sharp decline in BSI cases, which was not attributed to the downfall of COVID-19 cases. Conclusion : Combined prospective surveillance and environmental sampling helped to find out the sources and implementation of an intensive and insistent infection control program that are needed to control opportunistic pathogens mediated BSI.

Risk of Bloodstream Infection in Patients with Systemic Lupus Erythematosus Exposed to Prolonged Medium-to-High-Dose Glucocorticoids.

This study aimed to investigate the incidence rate and risk factors of bloodstream infection (BSI) in patients with systemic lupus erythematosus (SLE) exposed to medium to high doses of glucocorticoids. This study included 1109 treatment episodes with prolonged (≥4 weeks) medium-to-high-dose glucocorticoids (≥15mg/day prednisolone) in 612 patients with SLE for over 14 years. Clinical features regarding systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K), immunosuppressant use, and laboratory results were obtained from the electronic medical database. The primary outcome of this study was the 1-year incidence of BSI. The effect of clinical factors on the outcome was investigated using a generalized estimating equation. During a total of 1078.64 person-years, 30 cases of BSI occurred, with an incidence rate of 2.78 (95% confidence interval (CI) 1.88-3.97) per 100 person-years. Mortality rate of the treatment episodes with BSI was 16.7%, which was significantly higher than that in the other episodes (incidence rate ratio (IRR) 19.59, 95% CI 7.33-52.44). When the incidence rate of BSI was stratified by baseline glucocorticoid dose and SLEDAI-2K score, a higher incidence rate of BSI occurred as disease activity or baseline glucocorticoid dose increased. In the multivariable analysis, SLEDAI-2K ≥20 (adjusted IRR (aIRR) 4.66, 95% CI 2.17-10.00), initial baseline prednisolone ≥ 60mg/day (aIRR 2.42, 95% CI 1.11-5.32), and cumulative prednisolone dose ≥15mg/day during the previous 6 months (aIRR 2.13, 95% CI 1.03-4.40) significantly increased the risk of BSI. In patients with SLE exposed to prolonged medium-to-high-dose glucocorticoids, the 1-year incidence rate of BSI was significantly higher than previously reported in the general patients with SLE. Severe disease activity, and high-dose glucocorticoid treatment previously or at baseline increased the risk of BSI.

First case of bloodstream infection due to Caulobacter spp. associated with a postoperative meningitis

Caulobacter species are aerobic Gram-negative bacilli initially isolated from aquatic environments and are an uncommon cause of human infection. We report a case of bloodstream infection and postoperative meningitis caused by Caulobacter spp. that occurred in a 53-year old woman two weeks after surgery for a breast carcinoma cerebral metastasis. Polymerase chain reaction (PCR) amplification and sequencing of the 16S ribosomal DNA identified Caulobacter spp. in three blood cultures and two cerebrospinal fluid (CSF) cultures. Based on our susceptibility results, the patient was successfully treated by a 2-week course of iv imipenem followed by a 4-week course of oral trimethoprim-sulfamethoxazole.

Bacterial bloodstream infection in critically ill patients with COVID-19: a retrospective cohort study.

Intensive care unit (ICU) patients with coronavirus disease 2019 (COVID-19), have a high risk of developing bloodstream infections (BSIs). However, the characteristics of and risk factors for BSIs in these patients remain unclear. We aimed to identify prevalent causative pathogens of BSI and related factors in critically ill patients with COVID-19. This was a single-center, retrospective cohort study. We analyzed the clinical characteristics and outcomes of 201 ICU patients with COVID-19. Logistic regression analysis was conducted to identify factors associated with BSI occurrence. Furthermore, we identified the primary causative pathogens of BSIs. The study outcomes were death or ICU discharge. Among the 201 included patients, 43 (21.4%) patients developed BSI. The mortality rate was non-significantly higher in the BSI group than in the BSI group (65.1% versus 58.9%, p = 0.487). There were significant between-group differences in the obesity prevalence and sex distribution, but not corticosteroid usage. BSI occurrence was significantly associated with duration of mechanical ventilation (MV), presence of ventilator-associated pneumonia, use of neuromuscular blocking agents, length of stay in ICU (ICU LOS), high body mass index (BMI), and male sex. The main causative pathogens were Klebsiella pneumoniae, Acinetobacter baumannii, and Enterococcus faecalis. Multi-drug-resistant pathogens were found in 87% of cases. Regardless of the origin, the common risk factors for BSI were ICU LOS and MV duration. All BSIs were acquired within the hospital setting, with ≈60% of the cases being primary BSIs. A small proportion of the BSI cases were catheter-related (four cases, 6.2%). Ventilator-associated pneumonia and urinary tract infections were present in 25% and 9.4% of the BSI cases, respectively. On average, the first positive blood culture appeared ≈11.4 (±9.7) days after ICU admission. Elucidating the risk factors for and common pathogens of BSI can inform prompt management and prevention of BSIs.

779. PIDS Featured Oral Abstract: High Beta Lactam Exposure in Neonates with Bloodstream Infection Associated with Intestinal Dysbiosis and Enterococcus spp. Abundance in the Gut Microbiome

Abstract Background To characterize how antibiotic exposure impacts development and durability of intestinal dysbiosis and the acquisition of antibiotic resistance genes (ARGs) in the intestinal flora of premature infants in the Neonatal Intensive Care Unit (NICU), we established an infant gut microbiome biorepository (IGMB). Methods We performed prospective weekly stool collection in NICU patients meeting the following criteria: birthweight < 2000 g, postnatal age < 2 months and no diagnoses of congenital gut malformation or cyanotic heart disease. Cases were infants with bloodstream infections (BSI), defined as bacterial growth from blood culture; controls were infants with < 5 days of antibiotic exposure, no BSI nor necrotizing enterocolitis. We performed metagenomic analysis on 5–6 serial stool samples from each of the 10 cases and 10 controls (n= 100 stools). We used Wilcoxon rank sum tests for pairwise comparisons. Results From July 2021 to May 2022, 265 infants contributed 1,300 stool samples to the IGMB. In 7 of 8 BSI cases the causative pathogen was identified in the pre-BSI stool sample. Two more BSI cases did not have a pre-BSI stool sample. Microbiome species α-diversity increased with advancing postnatal age in controls but not in cases (Fig. 1). Among 6 cases with high beta lactam exposure ( >14 cumulative days by last stool collection), 3 had notable increases in the relative abundance of Enterococcus spp. (Fig. 2). Controls did not have similar trends in Enterococcus spp., but did have higher relative abundance of facultative anaerobes including Bifidobacterium, Lactobacillus, and Veillonella spp. (Fig. 3). Antibiotic resistance gene (ARG) abundance did not differ significantly between cases and controls. Conclusion Compared to controls, neonates with BSI have increased antibiotic intensity throughout their NICU admissions, reduction of microbial species diversity and overabundance of specific organisms in their gut microbiomes. We observed increased Enterococcus spp. prevalence with higher beta lactam exposure. ARG abundance did not differ between cases and controls. The clinical implications of this microbiome dysbiosis warrant further study. Disclosures Jörn-Hendrik Weitkamp, MD, Roche Diagnostics: Advisor/Consultant.

Differences in the distribution of pathogens and antimicrobial resistance in bloodstream infections in migrants compared with non-migrants in Denmark

Background We wish to study disparities in bloodstream infections in migrants and non-migrants by comparing the distribution of pathogens and their resistance patterns in long-term migrants with that in non-migrants in Denmark. Methods The study is based on a cohort of migrants, who received residency in Denmark between 1993 and 2015 and a control group of non-migrants. The cohort was linked to a database of bloodstream infections from 2000 to 2015 covering two regions in Denmark. First-time bloodstream infections in individuals ≥18 years of age at the time of sampling were included. We calculated odds ratios adjusted for age, sex, year of sampling, comorbidity, and place of acquisition (hospital- or community-acquired). Results We identified 4,703 bloodstream infection cases. Family-reunified migrants and refugees had higher odds of Escherichia coli than non-migrants (OR 1.89 95%CI: 1.46–2.44 and OR 1.55 95%CI: 1.25–1.92) and lower odds of Streptococcus pneumoniae (OR 0.38 95%CI: 0.21–0.67 and OR 0.52 95%CI: 0.34–0.81). Differences in pathogen distribution were only prevalent in community-acquired bloodstream infections. Refugees had higher odds of Escherichia coli resistant to piperacillin-tazobactam, ciprofloxacin, and gentamicin compared with non-migrants. Family-reunified migrants had higher odds of Escherichia coli and other Enterobacterales resistant to ciprofloxacin. Conclusions Migrants had a higher proportion of community-acquired bloodstream infections with Escherichia coli as well as higher odds of bloodstream infections with resistant Escherichia coli compared with non-migrants. These novel results are relevant for improving migrant health by focussing on preventing and treating infections especially with Escherichia coli such as urinary tract and abdominal infections.

Diagnostic and Therapeutic Utility of Positive Intravascular Catheter Tip Cultures.

This study evaluated the performance and clinical utility of performing intravascular catheter tip cultures (CTC). A retrospective chart review was conducted over a 2.5 year period on all patients who demonstrated growth of at least one organism on CTC. There were a total of 391 CTC performed. 88 (23%) grew at least one organism, while 303 (77%) had no growth. Of the positive CTC, 81 (92%) had blood cultures (BC) collected within 14 days, whereas 7 (8%) did not. Of the positive CTC with BC, 67 (83%) were BC-positive, whereas 14 (17%) were negative. For cases with growth on both CTC and BC, the organisms identified were concordant for 46 (69%) cases and discordant for 21 (31%). Of the concordant cases, 43 (93%) were clinically considered to be bacterial bloodstream infections that were secondary to a catheter infection. For all of the positive CTC cases total, there was no change in the antibiotics or management, with the exceptions of 2 out of 88 (2%) cases. Catheters were removed and cultured for an average of 38.6 h (range: -98 to 288 h) after positive BC results were available. Most CTC are negative, and for the CTC that are positive, most are concordant with BC results. CTC results are generally only available several days after positive BC results are known. The CTC results did not alter the antibiotic therapy or management, with the exceptions of rare cases. As such, this study concludes that CTC do not contribute diagnostic or therapeutic value. Therefore, current guidelines by the Infectious Diseases Society of America on catheter-related bloodstream infection diagnosis should be revised to exclude CTC collection. IMPORTANCE In patients with intravascular catheters who are febrile or have positive blood cultures and no other obvious sources of infection, catheter tip cultures are often obtained to evaluate potential catheter-related bloodstream infections. However, previous studies reported that the management of catheter-related bloodstream infection cases is entirely based on blood culture growth and susceptibilities and that catheter tip cultures have low diagnostic positive predictive value. Our study represents the largest contemporary evaluation that includes chart reviews on all positive catheter tip culture cases. We found that positive cultures led to no changes in antibiotics or management, except for in two cases. Furthermore, 92% of positive catheter tip cultures were associated with blood culture collections, and catheter cultures were generally available only several days after the blood culture results were known. Thus, our study supports the claim that positive catheter tip cultures add limited diagnostic and therapeutic value in suspected catheter-related bloodstream infections.

Impact of adherence to individual quality-of-care indicators on the prognosis of bloodstream infection due to Staphylococcus aureus: a prospective observational multicentre cohort

ObjectivesTo analyse the adherence and impact of quality-of-care indicators (QCIs) in the management of Staphylococcus aureus bloodstream infection in a prospective and multicentre cohort. MethodsAnalysis of the prospective, multicentre international S. Aureus Collaboration cohort of S. Aureus bloodstream infection cases observed between January 2013 and April 2015. Multivariable analysis was performed to evaluate the impact of adherence to QCIs on 90-day mortality. ResultsA total of 1784 cases were included. Overall, 90-day mortality was 29.9% and mean follow-up period was 118 days. Adherence was 67% (n = 1180/1762) for follow-up blood cultures, 31% (n = 416/1342) for early focus control, 77.6% (n = 546/704) for performance of echocardiography, 75.5% (n = 1348/1784) for adequacy of targeted antimicrobial therapy, 88.6% (n = 851/960) for adequacy of treatment duration in non-complicated bloodstream infections and 61.2% (n = 366/598) in complicated bloodstream infections. Full bundle adherence was 18.4% (n = 328/1784). After controlling for immortal time bias and potential confounders, focus control (adjusted hazard ratio = 0.76; 95% CI, 0.59–0.99; p 0.038) and adequate targeted antimicrobial therapy (adjusted hazard ratio = 0.75; 95% CI, 0.61–0.91; p 0.004) were associated with low 90-day mortality. DiscussionAdherence to QCIs in S. Aureus bloodstream infection did not reach expected rates. Apart from the benefits of application as a bundle, focus control and adequate targeted therapy were independently associated with low mortality.

Bacteriological profile of bloodstream infections at a tertiary care hospital in New Delhi

Invasion of the blood stream by microorganisms constitutes one of the most serious situations in infectious disease. Aim: The aim of this study was to identify the bacteria that caused blood stream infections. Methods: This six months prospective and observational study was performed in the department of microbiology at All India institute of Medical Science (AIIMS), New Delhi, India, on 280 blood samples of patients admitted in wards and various ICUs. Microbial detection and identification were done by fully automated BacT/Alert 3D and VITEK 2 systems, respectively. Results: Of the 280 suspected cases, blood culture was positive in 186 (66.4%) cases. Of the 186 isolates, 123 (66.12%) were Gram negative bacterial isolates of which the predominant were Klebsiella pneumoniae (27.64%), Pseudomonas aeruginosa (16.26%), and Escherchia coli (15.44%). Of the positive isolates, 63 (33.87%) were Gram positive bacteria of which MRSA (36.50%) was the predominant organism followed by MSSA (31.74%) and MRCoNS (17.46%). Conclusion: In this study, blood culture was positive in a relatively high proportion of suspected cases of blood stream infections. Automation has higher sensitivity and specificity than conventional methods and can help in significantly reducing mortality and morbidity of blood stream infections.

Femoral osteomyelitis caused by oral anaerobic bacteria with mixed bacteremia of Campylobacter rectus and Parvimonas micra in a chronic periodontitis patient: a case report

BackgroundCampylobacter rectus is a gram-negative rod, and Parvimonas micra is a gram-positive coccus, both of which are oral anaerobes that cause chronic periodontitis. Chronic periodontitis can cause bacteremia and systemic diseases, including osteomyelitis. Hematogenous osteomyelitis caused by anaerobic bacteria is uncommon, and to date, there have been no reports of mixed bacteremia with C. rectus and P. micra. Here, we report the first case of osteomyelitis of the femur caused by anaerobic bacteria with mixed bacteremia of C. rectus and P. micra caused by chronic periodontitis.Case presentationA 75-year-old man with chronic periodontitis, hyperuricemia, and benign prostatic hyperplasia was admitted to the hospital with a fracture of the left femur. The patient had left thigh pain for 4 weeks prior to admission. Left femoral intramedullary nail fixation was performed, and a large amount of abscess and necrotic tissue was found intraoperatively. The cultures of abscess specimens were identified as P. micra, Fusobacterium nucleatum, and C. rectus. C. rectus and P. micra were also isolated from blood cultures. C. rectus was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16 S ribosomal RNA sequencing. Sulbactam-ampicillin was administered for approximately 1 month, after which it was replaced by oral clavulanic acid-amoxicillin for long-term suppressive treatment.ConclusionsOnly five cases of bloodstream infection with C. rectus have been reported, and this is the first report of mixed bacteremia with P. micra. Clinicians should consider that chronic periodontitis caused by rare oral anaerobic bacteria can cause systemic infections, such as osteomyelitis.

PB2256: BACTERIAL BLOODSTREAM INFECTIONS AND ANTIMICROBIAL SUSCEPTIBILITY PATTERN IN PATIENTS WITH ACUTE LEUCAEMIA

Background: Currently, there is a trend towards an increasing proportion of Gram-negative microorganisms, including Enterobacterias. Escherichia coli and Klebsiella pneumoniae constitute the major part in the structure of bloodstream pathogens. One important mechanism of Enterobacterias’ resistance is the production of extended-spectrum beta-lactamases (ESBL), AmpC β-lactamases and carbapenemases. Aims: Determination of the antibiotic resistance profile of bloodstream pathogens in patients with acute leukaemia and evaluation of the efficacy of starting antibiotic therapy regimens. Methods: The study included 69 cases of bloodstream infections, confirmed by bacteriological blood testing in patients with acute leukaemia between January 2020 and January 2022, 46.4% of which were male and 53.6% were female, with a median age of 44 years. All patients had myelotoxic agranulocytosis at the time of infectious complications. Results: During the study period and according to the bacteriological examination of blood, 58 strains of E. coli and Kl. pneumoniae were detected. The antibiotic sensitivity pattern is shown in the figure. Bloodstream infection caused by E. coli was detected in 23 cases (32.8%), herewith ESBL production was detected in 47.8% of E. coli strains. In the scope of the empirical antibiotic therapy, the 4th generation cephalosporin (cefepime) was used in 39.1% of cases or carbapenem (meropenem) in 60.9% of cases in combination with the 3rd generation aminoglycoside (amikacin). Herewith the empirical antibiotic therapy was considered as rational in 78.3% of cases, whereas in the remaining cases escalation was essential. The use of the 4th generation cephalosporin (cefepime) in the scope of the empirical therapy was ineffective in 55.6% of cases. Due to the therapy in 95.7% of cases the patient’s condition was stable, and in 4.3% of cases led to a fatal outcome. Bloodstream infection caused by Kl. pneumoniae was detected in 35 cases (50%), and resistance to carbapenems was reported in 68.6% of strains of the Kl. pneumoniae. The share of ESBL-producing Kl. pneumonias trains was 40%, while the proportion of Enterobacteriaceae strains, susceptible to extended-spectrum cephalosporins and carbapenems, reached only 8.8%. During the therapy in 72.4% of cases the patient’s condition stabilised, and in 27.6% of cases a fatal outcome was recorded. In all cases of fatality сarbapenem-resistant strains, including panresistant strains (5.9%) acted as a causative agent. Summary/Conclusion: The most frequent causative agents of bloodstream infections in acute leukaemia patients during myelotoxic agranulocytosis are the Gram-negative bacteria E. coli and Kl. pneumoniae. The empirical antibiotic therapy regimens including 3rd generation cephalosporins (cefepime) was ineffective in 55.6% of cases, as 47.8% of isolated E. coli strains were generating ESBL. This increases the relevance of using carbapenems. Resistance to carbapenems was reported in 68.6% of strains of Kl. pneumoniae. This indicates a high prevalence of carbapenem-resistant strains in the haematological hospital, as well as the low efficacy of empirical antibiotic therapy, including both cephalosporins and carbapenems.

Nosocomial Infections During Extracorporeal Membrane Oxygenation in Pediatric Patients: A Multicenter Retrospective Study.

ObjectiveExtracorporeal membrane oxygenation (ECMO) is increasingly used in critically ill patients with respiratory and/or cardiac failure. This study aimed to investigate the epidemiology and risk factors of nosocomial infection (NI) in pediatric patients who underwent ECMO for respiratory and/or circulatory failure.MethodsMedical records for patients that were administered underwent ECMO support at Xiangya Second Hospital of Central South University, The Sixth Medical Center of PLA General Hospital, and Children's Hospital Affiliation of Zhengzhou University, from September 2012 to December 2019 were retrospectively reviewed. Clinical data of the patients who developed NI were collected and analyzed. Univariate and multivariate logistic regressions were performed to identify the independent predictive factors of NI during ECMO.ResultsA total of 54 first episodes of NI were identified in the 190 patients on ECMO, including 32 cases of respiratory tract infections, 20 cases of bloodstream infections, and 2 cases of surgical site wound infections. Gram-negative pathogens were the dominant pathogens isolated, accounting for 92.6% of the NI. The incidence of ECMO-related NI was 47.6 cases per 1,000 ECMO days. In the univariate logistic regression, ECMO mode, ECMO duration, ICU duration, and peritoneal dialysis were associated with the development of NI in patients with ECMO support. However, in the multivariate analysis, only ECMO duration (OR = 2.46, 95%CI: 1.10, 5.51; P = 0.029), ICU duration (OR = 1.35, 95%CI: 1.05, 1.59; P = 0.017) and peritoneal dialysis (OR = 2.69, 95%CI: 1.08, 5.73; P = 0.031) were the independent predictive factors for NI during ECMO support.ConclusionThis study identified the significant correlation between ECMO-related NI and ECMO duration, ICU duration, and peritoneal dialysis. Appropriate preventive measures are needed for hospitals to reduce the incidence of ECMO in pediatric patients.

An outbreak of Burkholderia cepacia bloodstream infections in a tertiary-care facility in northern India detected by a healthcare-associated infection surveillance network.

The burden of healthcare-associated infections (HAIs) is higher in low- and middle-income countries, but HAIs are often missed because surveillance is not conducted. Here, we describe the identification of and response to a cluster of Burkholderia cepacia complex (BCC) bloodstream infections (BSIs) associated with high mortality in a surgical ICU (SICU) that joined an HAI surveillance network. A 780-bed, tertiary-level, public teaching hospital in northern India. After detecting a cluster of BCC in the SICU, cases were identified by reviewing laboratory registers and automated identification and susceptibility testing outputs. Sociodemographic details, clinical records, and potential exposure histories were collected, and a self-appraisal of infection prevention and control (IPC) practices using assessment tools from the World Health Organization and the US Centers for Disease Control and Prevention was conducted. Training and feedback were provided to hospital staff. Environmental samples were collected from high-touch surfaces, intravenous medications, saline, and mouthwash. Between October 2017 and October 2018, 183 BCC BSI cases were identified. Case records were available for 121 case patients. Of these 121 cases, 91 (75%) were male, the median age was 35 years, and 57 (47%) died. IPC scores were low in the areas of technical guidelines, human resources, and monitoring and evaluation. Of the 30 environmental samples, 4 grew BCC. A single source of the outbreak was not identified. Implementing standardized HAI surveillance in a low-resource setting detected an ongoing Burkholderia cepacia outbreak. The outbreak investigation and use of a multimodal approach reduced incident cases and informed changes in IPC practices.

The hospital environment versus carriage: transmission pathways for third-generation cephalosporin-resistant bacteria in blood in neonates in a low-resource country healthcare setting

Neonatal bloodstream infections (BSI) can lead to sepsis, with high morbidity and mortality, particularly in low-income settings. The high prevalence of third-generation cephalosporin-resistant organisms (3GC-RO) complicates the management of BSI. Whether BSI is linked to carriage of 3GC-RO, or to acquisition from the hospital environment is important for infection prevention and control, but the relationship remains unclear, especially in low-income settings. At a tertiary hospital in Mwanza, Tanzania, we screened neonatal blood and rectal samples from 200 neonates, and 400 (hospital) environmental samples. We used logistic regression to identify risk factors, and Kolmogorov–Smirnov tests and randomisation analyses to compare distributions of species and resistance patterns to assess potential routes of transmission. We found that BSIs caused by 3GC-RO were frequent (of 59 cases of BSI, 55 were caused by 3GC-RO), as was carriage of 3GC-RO, particularly Escherichia coli, Klebsiella pneumoniae, and Acinetobacter species. In the 28 infants with both a carriage and blood isolate, there were more (4 of 28) isolate pairs of the same species and susceptibility profile than expected by chance (p < 0.05), but most pairs were discordant (24 of 28). Logistic regression models found no association between BSI and carriage with either 3GC-RO or only 3GC-R K. pneumoniae. These analyses suggest that carriage of 3GC-RO is not a major driver of BSI caused by 3GC-RO in this setting. Comparison with environmental isolates showed very similar distributions of species and resistance patterns in the carriage, BSI, and the environment. These similar distributions, a high frequency of Acinetobacter spp. isolations, the lack of strong association between carriage and BSI, together with the high proportion of 3GC-RO in BSI all suggest that these neonates acquire multidrug-resistant carriage and blood isolates directly from the hospital environment.

Increases in methicillin-sensitive Staphylococcus aureus bloodstream infection incidence, 2016–2019

Background: Incidence of methicillin-sensitive Staphylococcus aureus (MSSA) bloodstream infections (BSIs) in the United States during 2012–2017 has been reported to have been stable for hospital-onset BSIs and to have increased 3.9% per year for community-onset BSIs. We sought to determine whether these trends continued in more recent years and whether there were further differences within subgroups of community-onset BSIs. Methods: We analyzed CDC Emerging Infections Program active, population- and laboratory-based surveillance data during 2016–2019 for MSSA BSIs from 8 counties in 5 states. BSI cases were defined as isolation of MSSA from blood in a surveillance area resident. Cases were considered hospital onset (HO) if culture was obtained &gt;3 days after hospital admission and healthcare-associated community-onset (HACO) if culture was obtained on or after day 3 of hospitalization and was associated with dialysis, hospitalization, surgery, or long-term care facility residence within 1 year prior or if a central venous catheter was present ≤2 days prior. Cases were otherwise considered community-associated (CA). Annual rates per 100,000 census population were calculated for each epidemiologic classification; rates of HACO cases among chronic dialysis patients per 100,000 dialysis patients were calculated using US Renal Data System data. Annual increases were modeled using negative binomial or Poisson regression and accounting for changes in the overall population age group, and sex. Descriptive analyses were performed. Results: Overall, 8,344 MSSA BSI cases were reported. From 2016–2019 total MSSA BSI rates increased from 23.9 per 100,000 to 28.5 per 100,000 (6.6% per year; P &lt; .01). MSSA BSI rates also increased significantly among all epidemiologic classes. HO cases increased from 2.5 per 100,000 to 3.2 per 100,000 (7.9% per year; P = .01). HACO cases increased from 12.7 per 100,000 to 14.7 per 100,000 (7.0% per year; P = .01). CA cases increased from 8.4 per 100,000 to 10.4 per 100,000 (6.7% per year; P &lt; .01) (Fig. 1). Significant increases in MSSA BSI rates were also observed for nondialysis HACO cases (9.3 per 100,000 to 11.1 per 100,000; 7.8% per year; P &lt; .01) but not dialysis HACO cases (1,823.2 per 100,000 to 1,857.4 per 100,000; 1.4% per year; P = .59). Healthcare risk factors for HACO cases were hospitalization in the previous year (82%), surgery (31%), dialysis (27%), and long-term care facility residence (19%). Conclusions: MSSA BSI rates increased from 2016–2019 overall, among all epidemiologic classes, and among nondialysis HACO cases. Efforts to prevent MSSA BSIs among individuals with healthcare risk factors, particularly those related to hospitalization, might have an impact on MSSA BSI rates.Funding: NoneDisclosures: None

Emergence of Neonatal Sepsis Caused by MCR-9- and NDM-1-Co-Producing Enterobacter hormaechei in China.

Mobile colistin resistance (mcr) genes represent an emerging threat to public health. Reports on the prevalence, antimicrobial profiles, and clonality of MCR-9-producing Enterobacter cloacae complex (ECC) isolates on a national scale in China are limited. We screened 3,373 samples from humans, animals, and the environment and identified eleven MCR-9-positive ECC isolates. We further investigated their susceptibility, epidemiology, plasmid profiles, genetic features, and virulence potential. Ten strains were isolated from severe bloodstream infection cases, especially three of them were recovered from neonatal sepsis. Enterobacter hormaechei was the most predominant species among the MCR-9-producing ECC population. Moreover, the co-existence of MCR-9, CTX-M, and SHV-12 encoding genes in MCR-9-positive isolates was globally observed. Notably, mcr-9 was mainly carried by IncHI2 plasmids, and we found a novel ~187 kb IncFII plasmid harboring mcr-9, with low similarity with known plasmids. In summary, our study presented genomic insights into genetic characteristics of MCR-9-producing ECC isolates retrieved from human, animal, and environment samples with one health perspective. This study is the first to reveal NDM-1- and MCR-9-co-producing ECC from neonatal sepsis in China. Our data highlights the risk for the hidden spread of the mcr-9 colistin resistance gene.

Epidemiology and Drug Resistance of Neonatal Bloodstream Infection Pathogens in East China Children's Medical Center From 2016 to 2020.

IntroductionTo analyze the pathogen distribution and drug resistance of newborns with bloodstream infection (BSI) to help clinicians choose the appropriate empirical antibiotic therapy for clinical infection control.MethodsA total of 707 neonatal BSI cases were retrospectively analyzed. The bacteria in blood culture-positive samples were cultured, identified, and analyzed for drug sensitivity by routine methods. Statistical software was used to compare and analyze the basic data, pathogenic information, and drug resistance of the main bacteria.ResultsThe 5-year average positive rate of neonatal blood culture was 2.50%. The number of specimens submitted for inspection in 2020 significantly decreased. The top five infectious pathogens with the highest proportion were coagulase-negative Staphylococcus (67.35%), of which Staphylococcus epidermidis had the highest proportion (31.26%), followed by Escherichia coli (12.87%), Klebsiella pneumoniae (9.05%), Streptococcus agalactiae (8.63%), and Staphylococcus aureus (3.25%). Gram-positive (G+) bacteria were dominant, accounting for 69.45%. The main G+ bacteria had a higher rate of resistance to erythromycin and penicillin G. The main Gram-negative (G–) bacteria had a high resistance rate to a variety of antibacterial drugs, especially cephalosporin antibiotics. The overall resistance of K. pneumoniae was higher than that of E. coli. The top two fungi detected were Candida parapsilosis and Candida albicans. C. parapsilosis did not appear to be resistant to antibiotics, while C. albicans was resistant to multiple antibiotics. The type of microbial infection had a statistically significant difference in the positive rate among the age at delivery and wards (p < 0.05). There were significant differences in the detection of fungi among these groups (p < 0.05). The positive rate of G+ bacteria in the term newborns was significantly higher than that in the preterm newborns (p < 0.05). Preterm newborns are more susceptible to pneumonia.ConclusionG+ bacteria are the main pathogens of neonatal BSI. Preterm newborns are more likely to be infected with G– bacteria. E. coli and K. pneumoniae are the most common G– bacteria, and both have a high resistance rate to a variety of antibacterial drugs. According to the distribution characteristics and drug resistance, it is very important to select antibiotics reasonably.

Clinical and molecular characteristics of Streptococcus pneumoniae-associated hemophagocytic lymphohistiocytosis in children

Objective: To summarize the clinical features of Streptococcus pneumoniae-associated hemophagocytic syndrome (SP-HLH), and the serotypes and drug-resistant characteristics of the isolated strains. Methods: There were 15 children with SP-HLH admitted to the Pediatric Intensive Care Unit (PICU) of Beijing Children's Hospital, Capital Medical University from January 2013 to December 2020 were included in this study. Clinical data including children's general characteristics, clinical features, laboratory examinations, treatments, prognosis and the outcomes of follow-up by May 2021 were analyzed retrospectively. The serotypes and drug resistance of the isolated strains were identified. All children were divided into the clinical improvement group and the death group. Mann-Whitney U test, Fisher's exact test were used to compare the data of the two groups. Results: Among the 15 children with SP-HLH, 8 were males and 7 were females. The age of these children was 1.0 (1.0, 2.5) years. Regarding the primary infection, there were 9 cases of severe pneumonia, 3 cases of meningitis and 3 cases of blood stream infection. None of these children had received pneumoniae conjugate vaccine (PCV) and all of them were admitted to the PICU. Respiratory failure was observed in 10 patients, acute renal injury in 5, and hemolytic uremic syndrome in 3 patients. All children received glucocorticoids and high-dose intravenous immunogloblin (IVIG) in addition to anti-infective treatment. Eight of the children were cured while the other 7 died. The neutrophil count in the death group was lower than that in the clinical improvement group ((5.0 (1.7, 9.3) × 109 vs. 5.2 (3.4, 10.5) ×109/L, Z =-2.43, P<0.015), and the length of hospital stay and days of PICU stay in the death group were both shorter than those in the improvement group statistically (3 (1, 11) vs. 39 (34, 48) d, 2 (1, 4) vs. 19 (12, 31) d, Z=-3.25, -3.24, both P=0.001). Ten serotypes of Streptococcus pneumoniae were identified, including 4 strains of 19F, 3 of 19A, 1 of 23F, 1 of 15A and 1 of 14, among which 9 strains (9/10) were covered by PCV13. All strains were resistant to erythromycin yet sensitive to vancomycin and linezolid. Conclusions: SP-HLH is more common in children under the age of 3, with a high mortality rate. The death cases have lower neutrophil count and rapid disease progression. The comprehensive treatment is anti-infective combined with glucocorticoids and high-dose IVIG. The predominant serotypes are 19F and 19A and all isolated strains were susceptible to vancomycin and linezolid.

Epidemiology, resistant pathogens, and causes of early death in cases of bloodstream infection in patients with hematological malignancies from 2012–2019

PurposeTo investigate the epidemiology, causative pathogen antibiotic susceptibility, and mortality risk factors of bloodstream infection (BSI) in patients with hematological malignancies (HMs). MethodsSingle-center retrospective analysis of BSI cases in patients with HMs in a Chinese tertiary hospital from 2012–2019. ResultsAmong 17,796 analyzed admissions, 508 BSI episodes (2.9%; 95% confidence interval: 2.6%–3.2%) were identified. Of 522 resulting isolates, 326 (62.5%) were Gram-negative, 173 (33.1%) were Gram-positive. The BSI incidence among patients with different HMs (severe aplastic anemia: 6.7%; acute leukemia: 6.2%; myelodysplastic syndrome: 3.2%; multiple myeloma: 1.3%; and lymphoma: 1.0%) differed significantly (p < 0.001). The BSI incidence was significantly higher in the hematopoietic stem cell transplantation (HSCT) group (10.2%) than in the non-HSCT group (2.5%; p < 0.001). Escherichia coli (30.7%, 160/522) was the most common pathogen, followed by Coagulase-negative staphylococci (19.4%, 101/522) and Klebsiella pneumoniae (10.0%, 52/522)., The rates of imipenem resistance for E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii were 6.4%, 15.0%, 27.8%, and 79.0%, respectively. All the Gram-positive pathogens were linezolid susceptible. Three vancomycin-resistant Enterococcus species were isolated. The overall 14-day mortality was 9.8% (95% confidence interval: 7.2%–12.4%). A multivariate analysis showed that HM subtype severe aplastic anemia, A. baumannii, and malignancy non-remission were independent 14-day mortality risk factors. ConclusionsGram-negative bacteria were the most common pathogens, with E. coli as the predominant strain, causing BSIs in HM patients. A carbapenem-resistant A. baumanni with a high mortality rate in HM patients made empirical antimicrobial choice a highly challenging issue.

MRSA surveillance programmes worldwide: moving towards a harmonised international approach

Multinational surveillance programmes for methicillin-resistant Staphylococcus aureus (MRSA) are dependent on national structures for data collection. This study aimed to capture the diversity of national MRSA surveillance programmes and to propose a framework for harmonisation of MRSA surveillance. The International Society of Antimicrobial Chemotherapy (ISAC) MRSA Working Group conducted a structured survey on MRSA surveillance programmes and organised a webinar to discuss the programmes' strengths and challenges as well as guidelines for harmonisation. Completed surveys represented 24 MRSA surveillance programmes in 16 countries. Several countries reported separate epidemiological and microbiological surveillance. Informing clinicians and national policy-makers were the most common purposes of surveillance. Surveillance of bloodstream infections (BSIs) was present in all programmes. Other invasive infections were often included. Three countries reported active surveillance of MRSA carriage. Methodology and reporting of antimicrobial susceptibility, virulence factors, molecular genotyping and epidemiological metadata varied greatly. Current MRSA surveillance programmes rely upon heterogeneous data collection systems, which hampers international epidemiological monitoring and research. To harmonise MRSA surveillance, we suggest improving the integration of microbiological and epidemiological data, implementation of central biobanks for MRSA isolate collection, and inclusion of a representative sample of skin and soft-tissue infection cases in addition to all BSI cases.