Recent Antibiotic Exposure Research Articles

Amyloid A and lactic acid as a predictor in patients with sepsis in patients with liver cirrhosis

BackgroundSepsis is triggered by pathogenic microorganisms, resulting in a systemic inflammatory response. Liver cirrhosis and sepsis create a vicious cycle: cirrhosis weakens immune function, raising infection risk and hindering pathogen clearance. Optimal treatment outcomes depend on understanding liver cirrhosis patients’ sepsis risk factors. Thus, preventing sepsis involves addressing these risk factors. Therefore, early identification and understanding of clinical characteristics in liver cirrhosis patients with sepsis are crucial for selecting appropriate antibiotics. A case-control study using logistic regression was conducted to examine the prognostic value of amyloid A/lactate level monitoring in identifying sepsis risk factors in liver cirrhosis patients.MethodsFrom March 2020 to March 2022, 136 liver cirrhosis patients treated at our hospital were divided into a sepsis group (n = 35) and a non-sepsis group (n = 101) based on sepsis complications. General clinical data were collected. Univariate analysis screened for liver cirrhosis patients’ sepsis risk factors. Multivariate logistic analysis was subsequently employed to evaluate the risk factors. Sepsis patients were followed up for a month. Based on prognosis, patients were categorized into a poor prognosis group (n = 16) and a good prognosis group (n = 19). Serum amyloid A (SAA) and blood lactic acid (BLA) levels were compared between the two groups. The receiver operating characteristic (ROC) curve was used to evaluate the prognostic value of both individual and combined SAA/BLA monitoring.ResultsPatient data, including age, diabetes history, liver cancer, hepatic artery embolization, recent antibiotic use, invasive procedures within two weeks, APACHE II Scoring, ALB and SAA and BLA levels, were compared between the sepsis and non-sepsis groups, showing significant differences (P < 0.05). Logistic regression identified factors such as age ≥ 70, recent antibiotic use, recent invasive procedures, history of liver cancer, hepatic artery embolization history, high APACHE II scores, decreased albumin, and elevated SAA and BLA levels as independent sepsis risk factors in liver cirrhosis patients (P < 0.05). Among the 35 sepsis patients, 16 had a poor prognosis, representing an incidence rate of 45.71%. Serum SAA and BLA levels were significantly higher in the poor prognosis group than in the good prognosis group (P < 0.05). The AUC for serum SAA and BLA was 0.831 (95%CI: 0.738–0.924), 0.720 (95%CI: 0.600–0.840), and 0.909 (95%CI: 0.847–0.972), respectively. The combined diagnostic AUC was significantly higher than that of single factor predictions (P < 0.05). The predictive value ranked as follows: joint detection > SAA > BLA.ConclusionIn treating liver cirrhosis, prioritize patients with advanced age, a history of hepatic artery embolization, recent invasive operations, history of liver cancer, recent antibiotic exposure, high APACHE II scores and low albumin. Closely monitoring serum SAA and BLA levels in these patients can offer valuable insights for early clinical prevention and treatment.

Phase I/II trial of healthy donor fecal microbiota transplant (hdFMT) in PD-1 relapsed/refractory (R/R) non-small cell lung cancer (NSCLC).

TPS8648 Background: A significant portion of patients (pts) with advanced NSCLC either do not respond or become refractory to immune checkpoint inhibitor (ICI) therapy administered alone or in combination with platinum chemotherapy. In addition to tumor-intrinsic mechanisms supporting resistance to anti-PD-1, the gut microbiome is a major tumor-extrinsic regulator of responses to anti-PD-1. In mice, gut microbiota modulate therapeutic activity of anti-PD-1 ICI, and administration of gut commensals or responder-derived fecal microbiota transplantation (R-FMT) promotes anti-PD-1 efficacy. Longitudinal analyses of gut microbiome samples from ICI-treated cancer pts suggests key bacterial species are associated with favorable response, although limited concordance among the identified species has been reported across studies. We and others have previously demonstrated that microbiome modulation reversed anti-PD-1 resistance in anti-PD-1 R/R melanoma, and augmented benefit of anti-PD-1 monotherapy in ICI-naïve melanoma. We hypothesize that intestinal dysbiosis mediates anti-PD-1 resistance in anti-PD-1 R/R NSCLC, and that hdFMT may resensitize NSCLC to PD-1 blockade. Methods: This is an investigator-initiated, phase II trial of hdFMT with pembrolizumab (P) in pts with R/R NSCLC progressed on prior anti-PD-1 based therapy alone or in combination with platinum chemotherapy. Pts must have measurable disease per RECIST v1.1, no untreated CNS metastases, and no contraindications to FMT administration. hdFMT is derived from non-obese, healthy, adults aged ≥18 to &lt;70, with no chronic diseases, and no recent antibiotic exposure. Donors are screened broadly for transmissible agents including SARS-CoV-2 using bookend screening. hdFMT is processed to make fecal infusates and orally bioavailable capsules. Eligible pts receive P 200mg every 3 weeks (Q3W). hdFMT is administered endoscopically on D1, and D42, and thereafter via capsules until progression or unacceptable toxicity. Response is assessed at D73, and thereafter Q12W. Pts undergo tumor biopsies at baseline and at W8, with optional post-progression biopsy. Primary endpoint: overall response rate (ORR) assessed using RECIST v1.1 by Blinded Independent Central Review (BICR). Secondary endpoints include: safety, progression-free survival (PFS), overall survival (OS), and landmark PFS/OS. Key translational endpoints include immune activation (tumor tissue, blood), metagenomic engraftment, and transcriptomic analyses of intestinal luminal myeloid cells and exfoliome. The null hypothesis that the true ORR is 5% will be tested versus a 1-sided alternative hypothesis of ≥25%, using Simon’s minimax two-stage design (type I error 0.04, power 0.9, when true response rate is 0.25). PFS and OS will be estimated via Kaplan-Meier method. Enrollment has commenced. Clinical trial information: NCT05669846 .

Randomized phase II trial of pembrolizumab/lenvatinib (P+L) +/- responder fecal microbiota transplant (R-FMT) in PD-1 relapsed/refractory (R/R) cutaneous melanoma (MEL).

TPS9607 Background: A significant portion of patients (pts) with advanced MEL develop resistance to immune checkpoint inhibitors (ICI). The gut microbiome is a major tumor-extrinsic regulator of ICI response. In mice, gut microbiota modulate therapeutic activity of ICI, and administration of certain gut commensals or responder-derived fecal microbiota transplantation (R-FMT) promotes anti-PD-1 efficacy in melanoma-bearing mice. In the LEAP-004 trial, P+L produced 21% ORR in PD-1 R/R MEL with Gr3+ TRAE 45.6%. Longitudinal analyses of gut microbiome samples from ICI-treated cancer pts suggests key species including Actinobacteria and Firmicutes are associated with favorable response. We and others have previously demonstrated that microbiome modulation using R-FMT reversed PD-1 non-response in PD-1 R/R MEL. In PD-1 naïve MEL, healthy donor FMT (hdFMT) augments benefit of PD-1 monotherapy. We hypothesized that intestinal dysbiosis mediates PD-1 resistance in PD-1 R/R MEL, microbiome modulation may reverse TKI toxicity, and that R-FMT may resensitize MEL to PD-1 blockade. Methods: This is an investigator-initiated, randomized, phase II trial of P+L vs. P+L+R-FMT in PD-1 R/R MEL. Pts must have measurable disease per RECIST v1.1, no active CNS metastases (or if present, previously treated and stable on repeat imaging), and no contraindications to FMT administration. R-FMT is derived from non-obese, advanced MEL with durable response (mPFS ≥24 months) following prior PD-1 ICI, with no recent (≤1 month) antibiotic exposure. Donors are screened broadly for infectious agents including SARS-CoV-2 using bookend screening. R-FMT is processed to make fecal infusates and orally bioavailable capsules. Eligible pts are randomized 1:1 to either P+L [P 200mg every 3 weeks (Q3W) along with L 20mg orally once daily] or P+L+R-FMT. R-FMT is administered endoscopically on D1, and D42, and thereafter via capsules until progression or unacceptable toxicity. Response is assessed at D73, and thereafter Q12W. Pts undergo biopsies at baseline and W8, with optional biopsy at progression. Primary endpoint: ORR assessed using RECIST v1.1 by Blinded Independent Central Review (BICR). Secondary endpoints include: safety, progression-free survival (PFS), overall survival (OS), and landmark PFS/OS. Key translational endpoints include immune activation (tumor tissue, blood), metagenomic engraftment, and transcriptomic analyses of intestinal luminal myeloid cells and exfoliome. The null hypothesis that the true ORR is 20% will be tested versus a one-sided alternative hypothesis of ≥50%. This design has a type I error rate 0.10 and power 0.8 when the true response rate is 0.25. Enrollment has commenced. Clinical trial information: NCT06030037 .

Sepsis and case fatality rates and associations with deprivation, ethnicity, and clinical characteristics: population-based case–control study with linked primary care and hospital data in England

PurposeSepsis is a life-threatening organ dysfunction caused by dysregulated host response to infection. The purpose of the study was to measure the associations of specific exposures (deprivation, ethnicity, and clinical characteristics) with incident sepsis and case fatality.MethodsTwo research databases in England were used including anonymized patient-level records from primary care linked to hospital admission, death certificate, and small-area deprivation. Sepsis cases aged 65–100 years were matched to up to six controls. Predictors for sepsis (including 60 clinical conditions) were evaluated using logistic and random forest models; case fatality rates were analyzed using logistic models.Results108,317 community-acquired sepsis cases were analyzed. Severe frailty was strongly associated with the risk of developing sepsis (crude odds ratio [OR] 14.93; 95% confidence interval [CI] 14.37–15.52). The quintile with most deprived patients showed an increased sepsis risk (crude OR 1.48; 95% CI 1.45–1.51) compared to least deprived quintile. Strong predictors for sepsis included antibiotic exposure in prior 2 months, being house bound, having cancer, learning disability, and diabetes mellitus. Severely frail patients had a case fatality rate of 42.0% compared to 24.0% in non-frail patients (adjusted OR 1.53; 95% CI 1.41–1.65). Sepsis cases with recent prior antibiotic exposure died less frequently compared to non-users (adjusted OR 0.7; 95% CI 0.72–0.76). Case fatality strongly decreased over calendar time.ConclusionGiven the variety of predictors and their level of associations for developing sepsis, there is a need for prediction models for risk of developing sepsis that can help to target preventative antibiotic therapy.

Importance of underlying mechanisms for interpreting relative risk of Clostridioides difficile infection among antibiotic-exposed patients in healthcare facilities.

Clostridioides difficile infection (CDI) is a significant public health threat, associated with antibiotic-induced disruption of the normally protective gastrointestinal microbiota. CDI is thought to occur in two stages: acquisition of asymptomatic colonization from ingesting C. difficile bacteria followed by progression to symptomatic CDI caused by toxins produced during C. difficile overgrowth. The degree to which disruptive antibiotic exposure increases susceptibility at each stage is uncertain, which might contribute to divergent published projections of the impact of hospital antibiotic stewardship interventions on CDI. Here, we model C. difficile transmission and CDI among hospital inpatients, including exposure to high-CDI-risk antibiotics and their effects on each stage of CDI epidemiology. We derive the mathematical relationship, using a deterministic model, between those parameters and observed equilibrium levels of colonization, CDI, and risk ratio of CDI among certain antibiotic-exposed patients relative to patients with no recent antibiotic exposure. We then quantify the sensitivity of projected antibiotic stewardship intervention impacts to alternate assumptions. We find that two key parameters, the antibiotic effects on susceptibility to colonization and to CDI progression, are not identifiable given the data frequently available. Furthermore, the effects of antibiotic stewardship interventions are sensitive to their assumed values. Thus, discrepancies between different projections of antibiotic stewardship interventions may be largely due to model assumptions. Data supporting improved quantification of mechanistic antibiotic effects on CDI epidemiology are needed to understand stewardship effects better.

705. Burden of Medically-Attended Diarrhea and Clostridioides difficile Infection (CDI) Among Persons in the Community in an Integrated Healthcare Setting, 2016-2021

Abstract Background Population-based surveillance by the Centers for Disease Control and Prevention (CDC) indicates that the incidence of community-associated Clostridioides difficile infection (CDI) is increasing. However, CDI testing practices and incidence among patients seeking care for diarrhea in the outpatient setting have not been well described. Further, little is known about healthcare utilization and outcomes of patients with medically-attended CDI who are not subsequently hospitalized. Methods We conducted a retrospective cohort study of Kaiser Permanente Southern California (KPSC) and Northwest (KPNW) adult (≥ 18 years of age) members from January 1, 2016 to December 31, 2021. We identified medically-attended diarrhea (MAD) in the outpatient setting through ICD-10 diagnosis codes. Among those with MAD, we identified C. difficile testing and outpatient CDI (oCDI), defined as a positive CDI test without hospitalization in the following 0-7 days. We described the demographic and clinical characteristics of patients with MAD and oCDI and calculated incidence rates (IR) of oCDI. We also described the occurrence of oCDI-associated healthcare visits, CDI testing, and oCDI treatment in the 12 months following oCDI diagnosis. Results We identified 777,533 outpatient MAD episodes of which 93,964 (12.1%; 93,964/777,533) were tested for CDI. Among tested episodes, 10,110 (10.8%; 10,110/93,964)), involving 9,517 patients, had a positive CDI laboratory test. IR of outpatient oCDI decreased from 58.2 (95%CI: 55.7-60.7) per 100,000 person-years (PY) in 2016 to 45.7 (43.7-47.8) per 100,000 PY in 2021. Among 9,517 oCDI patients, 84.1% (n=8,006) CDI were ‘community-associated’ (without hospitalizations in the 84 days prior to index date) and only 44.1% (n=4,200) received an antibiotic in the previous 30 days. Only 6.7% (n=526) of oCDI patients had a CDI-associated hospitalization in the 12 months after diagnosis. Conclusion There was a high incidence of MAD and CDI in among outpatients. The majority of our outpatient CDI population had no recent hospitalization and no recent antibiotic exposure. Further studies are needed to understand the factors associated with CDI diagnosed and managed in the outpatient setting. Disclosures Sara Y. Tartof, PhD MPH, Genentech: Grant/Research Support|GSK: Grant/Research Support|Pfizer: Grant/Research Support|SPERO: Grant/Research Support Mark A. Schmidt, PhD, MPH, Intercept Pharmaceuticals: Grant/Research Support|Pfizer: Grant/Research Support|Vir Biotechnology: Grant/Research Support Fredrick J. Angulo, DVM, PhD, Pfizer Vaccines: Employee|Pfizer Vaccines: Employee|Pfizer Vaccines: Stocks/Bonds|Pfizer Vaccines: Stocks/Bonds Ana Florea, PhD MPH, Gilead: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Moderna: Grant/Research Support|Pfizer: Grant/Research Support Joann M. Zamparo, MPH, Pfizer Inc.: Full Time Employee|Pfizer Inc.: Stocks/Bonds Deborah S. Ling Grant, PhD, MPH, MBA, Pfizer: Grant/Research Support Elisa Gonzalez, MPH, Pfizer: Stocks/Bonds Jennifer L. Kuntz, MS, PhD, Pfizer: Grant/Research Support

355. Stratification of Patient-Specific Risk Factors for Multidrug-Resistant Gram-Negative Respiratory Pathogens in Intensive Care Units (ICU)

Abstract Background Guidelines for nosocomial pneumonia recommend empiric combination therapy for patients with a risk of infection due to multidrug-resistant Gram-negative pathogens in ICUs. Common risk factors cited include ≥ 5-day duration in the ICU, transfer from other healthcare facilities, recent antibiotic use, and history of a resistant Gram-negative pathogen. However, the interrelation of these factors and which are key drivers remain ill-defined. This study is designed to stratify risk factors to further optimize empiric regimens. Methods A total of 190 patients who had a positive Gram-negative respiratory culture obtained from the MICU/SICU of Michigan Medicine in 2021 were included. Patients were classified into subgroups based on the presence/absence of each aforementioned risk factor. Cumulative susceptibility percentages of isolates in each risk group were examined and compared. Results Cumulative susceptibility percentages of Gram-negative respiratory isolates from patients with/without each risk factor are shown in Figure 1. Patients with recent antibiotic use or history of a resistant Gram-negative pathogen had noticeably lower susceptibility rates than those without those risk factors, whereas the presence/absence of prolonged ICU stay and/or admission from another facility had minimal impact on susceptibility rates. In patients without recent antibiotic exposure or history of a resistant pathogen, 90% had pathogens that demonstrated in vitro susceptibility to cefepime monotherapy. (Figure 2) In contrast, the susceptibility percentages of any β-lactam monotherapy were &amp;lt; 75% in patients with one or more of these factors and remained &amp;lt; 85% when adding an aminoglycoside or fluoroquinolone. More stratified analyses demonstrated that patients with previous positive carbapenem-resistant P. aeruginosa or Enterobacterales should receive a novel agent. Proposed stratified empiric regimens are summarized in Figure 3. Conclusion Recent antibiotic use and previous positive resistant Gram-negative cultures were significant factors for determining antibiotic resistance in Gram-negative respiratory pathogens. Risk stratification based on these two factors can help further optimize empiric antibiotic therapy. Disclosures jason M. Pogue, PharmD, AbbVie: Advisor/Consultant|Entasis: Advisor/Consultant|Ferring: Advisor/Consultant|GSK: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Qpex: Advisor/Consultant|Shionogi: Advisor/Consultant

Infectious complications of transrectal prostate biopsy in patients receiving targeted antibiotic prophylaxis after urethral and rectal swab versus standard prophylaxis: A prospective comparative study

BackgroundTo evaluate the role of targeted antibiotic prophylaxis (TAP) after rectal and urethral swab cultures compared to empiric antibiotic prophylaxis (EAP) for the prevention of infectious complications after transrectal ultrasound-guided prostate biopsy (TRUS-Bx). MethodsWe conducted a prospective comparative study on 141 patients who underwent TRUS-Bx and were allocated in two groups. The first group (n = 71) received EAP with ciprofloxacin and the second (n = 70) received TAP according to rectal and urethral cultures. Post-biopsy infectious complications rates were compared between the two groups. Fluoroquinolone resistance (FQ-R) in the urethral and rectal swabs was recorded. Baseline characteristics were analyzed to assess their relationship with infectious complications and antibiotic resistance. ResultsA total of 8 infectious complications were observed, 7 of them in the EAP group (9.85%) and 1 in the TAP group (1.4%). There was a statistically significant difference in febrile UTIs between the two groups (6 vs 0, P = 0.028). FQ-R rate was 4.3% and 12.9% for rectal and urethral samples, respectively. Recent antibiotic exposure was associated with higher post-biopsy infection rates for EAP group and FQ-R rates for TAP group. ConclusionCombination of rectal and urethral swab cultures for TAP was able to detect FQ-R bacteria carriers and was associated with fewer infectious complications compared to EAP.

Childhood infection burden, recent antibiotic exposure and vascular phenotypes in preschool children.

Severe childhood infection has a dose-dependent association with adult cardiovascular events and with adverse cardiometabolic phenotypes. The relationship between cardiovascular outcomes and less severe childhood infections is unclear. To investigate the relationship between common, non-hospitalised infections, antibiotic exposure, and preclinical vascular phenotypes in young children. A Dutch prospective population-derived birth cohort study. Participants were from the Wheezing-Illnesses-Study-Leidsche-Rijn (WHISTLER) birth cohort. We collected data from birth to 5 years on antibiotic prescriptions, general practitioner (GP)-diagnosed infections, and monthly parent-reported febrile illnesses (0-1 years). At 5 years, carotid intima-media thickness (CIMT), carotid artery distensibility, and blood pressure (BP) were measured. General linear regression models were adjusted for age, sex, smoke exposure, birth weight z-score, body mass index, and socioeconomic status. Recent antibiotic exposure was associated with adverse cardiovascular phenotypes; each antibiotic prescription in the 3 and 6 months prior to vascular assessment was associated with an 18.1 μm (95% confidence interval, 4.5-31.6, p = 0.01) and 10.7 μm (0.8-20.5, p = 0.03) increase in CIMT, respectively. Each additional antibiotic prescription in the preceding 6 months was associated with an 8.3 mPa-1 decrease in carotid distensibility (-15.6- -1.1, p = 0.02). Any parent-reported febrile episode (compared to none) showed weak evidence of association with diastolic BP (1.6 mmHg increase, 0.04-3.1, p = 0.04). GP-diagnosed infections were not associated with vascular phenotypes. Recent antibiotics are associated with adverse vascular phenotypes in early childhood. Mechanistic studies may differentiate antibiotic-related from infection-related effects and inform preventative strategies.

Look What the Cat Dragged in! Recurrent Clostridioides difficile from a Household Cat.

BACKGROUND Clostridioides difficile (C. difficile) is a bacterium that is well known for causing serious diarrheal infections and can even lead to colon cancer if left untreated. Disruption of the normal healthy bacteria in the colon can lead to development of C. difficile colitis. Risk factors for C. difficile infections (CDI) include recent antibiotic exposure, hospital or nursing home stays, inflammatory bowel disease (IBD), or impaired immunity. There is an increasing incidence of community-associated CDI (CA-CDI) in individuals without the common risk factors, which has implicated natural reservoirs, zoonoses, originating from animals such as domestic cats and dogs, livestock, shellfish, and wild animals. CASE REPORT A previously healthy 31-year-old woman with recurrent CA-CDI suspected to be acquired from a household cat represents a novel presentation. The patient had an initial case of severe diarrhea following recent antibiotic exposure, was briefly monitored in hospital, and was diagnosed with CDI. She was trialed on oral vancomycin, which resulted in temporary resolution of her symptoms. Her symptoms recurred, however, and did not improve despite treatment with multiple therapeutic options over a period of months. Ultimately, the patient was not able to achieve long-term resolution of her symptoms until her newly adopted pet cat was treated by a veterinarian. CONCLUSIONS In conclusion, this case report explores the epidemiologic risk factors of zoonotic CA-CDI and the importance of early identification, evaluation, and prevention of disease. This case demonstrates the significance of thorough history taking, contact (pet) tracing, and proper treatment of recurrent CA-CDI.

The Molecular Epidemiology of Clostridioides difficile Infection in Central India: A Prospective Observational Cohort Study

This prospective observational cohort study aimed to establish and compare baseline rates of Clostridioides difficile infection (CDI) in community and hospitalized patients in Nagpur and rural Melghat Maharashtra, including adults aged ≥18 years with a diagnosis of diarrhoea as defined as 3 or more loose stools in a 24 h period. All diarrhoeal samples were tested for CDI using the C. diff Quik Chek Complete enzyme immunoassay. C. difficile-positive stool samples were characterised by toxigenic culture, antimicrobial susceptibility testing and PCR ribotyping. C. difficile testing was performed on 1683 patients with acute diarrhoea. A total of 54 patients (3.21%; 95% CI: 2.42–4.17) tested positive for both the GDH antigen and free toxin. The risk factors for CDI included the presence of co-morbidities, antibiotic usage, and immunosuppression. The detected PCR ribotypes included 053-16, 017, 313, 001, 107, and 216. Our findings show that toxigenic C. difficile is an important but neglected aetiologic agent of infective diarrhoea in Central India. These results underscore the need to enhance the awareness and testing of patients with diarrhoea in India regarding the presence of toxigenic C. difficile, particularly in high-risk individuals with multiple co-morbidities, immunosuppression, and recent or ongoing antibiotic exposure or hospitalization.

Risk Factors, Temporal Dependence, and Seasonality of Human Extended-Spectrum β-Lactamases-Producing Escherichia coli and Klebsiella pneumoniae Colonization in Malawi: A Longitudinal Model-Based Approach.

Sub-Saharan Africa has the highest estimated death rate attributable to antimicrobial resistance, especially from extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E). However, the dynamics of human colonization in the community with ESBL-E are not well described. Inadequate water, sanitation, and hygiene infrastructure and associated behaviors are believed to play an important role in transmission of ESBL-E, and an improved understanding of the temporal dynamics of within-household transmission could help inform the design of future policies. In this 18-month study, using microbiological data and household surveys, we built a multivariable hierarchical harmonic logistic regression model to identify risk factors for colonization with ESBL-producing Escherichia coli and Klebsiella pneumoniae, reflecting household structure and temporal correlation of colonization status. Being male was associated with a lower risk of colonization with ESBL-producing E. coli (odds ratio [OR], 0.786; credible interval [CrI], .678-.910), whereas the use of a tube well or a borehole was associated with an increased risk (OR, 1.550; CrI, 1.003-2.394). For ESBL-producing K. pneumoniae, recent antibiotic exposure increased risk of colonization (OR, 1.281; CrI, 1.049-1.565), whereas sharing plates decreased that risk (OR, 0.672; CrI, .460-.980). Finally, the temporal correlation range of 8 to 11 weeks provided evidence that within-household transmission occurs within this time frame. We describe different risks for colonization with different enteric bacterial species. Our findings suggest interventions to reduce transmission targeted at the household level need to focus on improving water, sanitation, and hygiene infrastructure and associated behaviors, whereas at the community level, they should focus on both environmental hygiene and antibiotic stewardship.

Utility of Metagenomic Next-Generation Sequencing in Infective Endocarditis: A Systematic Review.

Blood cultures have been the gold standard for identifying pathogens in infective endocarditis (IE). Blood culture-negative endocarditis (BCNE), however, occurs in 40% or more of IE cases with the bulk of them due to recent antibiotic exposure prior to obtaining blood cultures. Increasingly, molecular techniques are being used for pathogen identification in cases of BCNE and more recently has included metagenomic next-generation sequencing (mNGS). We therefore performed a literature search on August 31, 2022, that assessed the mNGS in IE and 13 publications were identified and included in a systematic review. Eight (61.5%) of them focused only on IE with mNGS performed on cardiac valve tissue in four studies, plasma in three studies and cardiac implantable electronic devices (CIED) in one study. Gram-positive cocci, including Staphylococcus aureus (n = 31, 8.9%), coagulase-negative staphylococci (n = 61, 17.6%), streptococci (n = 130, 37.5%), and Enterococcus&amp;nbsp;faecalis (n = 23, 6.6%) were the predominant organisms identified by mNGS. Subsequent investigations are needed to further define the utility of mNGS in BCNE and its impact on patient outcomes. Despite some pitfalls, mNGS seems to be of value in pathogen identification in IE cases, particularly in those with BCNE. This study was registered and on the Open Science Framework platform.

Septic Pulmonary Embolism: A Contemporary Profile.

Septic pulmonary embolism (SPE) is a rare clinical entity that is distinct from the classic and more common non-septic thrombotic pulmonary embolism. SPE should be suspected in patients with a systemic acute inflammatory reaction or sepsis who develop signs and symptoms of pulmonary involvement. The diagnosis of SPE depends on the specific radiologic finding of multiple, peripheral, nodular, possibly cavitated lesions. SPE should prompt an immediate search for the primary source of infection; typically, right-sided infective endocarditis, cardiac implantable electronic devices, and septic thrombophlebitis as a complication of bone, skin, and soft tissue infection including Lemierre's syndrome, indwelling catheters, or direct inoculation via injection drug use. Invasive treatment of the infection source may be necessary; in thrombophlebitis, the efficacy and safety of anticoagulation remain undefined. Blood cultures may be negative, particularly among patients with recent antibiotic exposure, and broad-spectrum antimicrobial therapy should be considered. The in-hospital mortality of SPE ranges up to 20% in published case series. While trends in the incidence of SPE are unknown, the opioid epidemic, the growing use of cardiac implantable electronic devices worldwide, and the reported increase in cases of septic thrombophlebitis may be leading to an escalation in SPE cases. We provide a contemporary profile of SPE and propose a clinical management algorithm in patients with suspected or confirmed SPE.

Prior Antibiotic Exposure Is Associated With Reoperation After Elective Non-colorectal Surgery.

Recent antibiotic exposure has previously been associated with poor outcomes following elective surgery. The purpose of this study is to evaluate the impact of prior recent antibiotic exposure in a multicenter cohort of Veterans Affairs patients undergoing elective non-colorectal surgery. This is a retrospective cohort study of the Veterans Affairs Surgical Quality Improvement Program, including elective, non-cardiovascular, non-colorectal surgery from 2013 to 2017. Outpatient antibiotic exposure within 90days prior to surgery was identified from the Veterans Affairs outpatient pharmacy database and matched with each case. Primary outcomes included serious complication, any complication, any infection, or surgical site infection. Secondary outcomes included 30-day mortality, length of stay, and Clostridioides difficile infection. Of 21,112 eligible patients, 2885 (13.7%) were exposed to antibiotics within 90days prior to surgery with a duration of 7 (IQR: 5-10) days and prescribed 42 (IQR: 21-64) days prior to surgical intervention. Compared to non-exposed patients, exposed patients had higher unadjusted complication rates, increased length of stay, and rates of return to the operating. Exposure was independently associated with return to the operating room (OR: 1.39; 99% CI: 1.05-1.84). Among Veterans, recent antibiotic exposure within 90days of elective surgery was associated with a 39% increase in the odds of return to the operating room. Further work is needed to evaluate the effects of antibiotic exposure and dysbiosis on surgical outcomes.

Epidemiology of Clostridioides difficile Infection in Portugal: A Retrospective, Observational Study of Hospitalized Patients.

Clostridioides difficile is the main cause of healthcare-associated diarrhea in Europe and North America. The aim of this study was to characterize the epidemiology and clinical burden of Clostridioides difficile infection among hospitalized patients in Portugal. Retrospective study conducted in six public hospital centers in Portugal. All primary Clostridioides difficile infection episodes and related recurrences occurring in 2017, as well as episodes developing two to eight weeks after the last episode diagnosed in that year, were documented. The National Reference Laboratory (National Institute of Health Dr. Ricardo Jorge) provided national surveillance data on Clostridioides difficile infection. A total of 385 inpatients with at least one primary episode diagnosed in 2017 were included. Most patients were aged over 70 years-old (73.2%). The included patients developed 451 episodes during the observation period. Approximately 44% of primary episodes were community-associated. Most episodes (94.9%) occurred in patients with one or more risk factors, with recent antibiotic exposure being particularly common (86.0%). All-cause in-hospital mortality was 19.5%, being significantly higher in patients aged over 65 years-old versus those aged 18 to 64 years-old (22.4% vs 7.8%, respectively). Over 50 different ribotypes were observed among 206 Clostridioides difficile strains received by the National Reference Laboratory. In Portugal, hospitalized patients with Clostridioides difficile infection are mostly older patients presenting risk factors for the development of this infection, particularly recent antibiotic exposure. Mortality is disproportionately high among the older population. Community-associated Clostridioides difficile infection is common among inpatients with this infection.

A Child's urine is not sterile: A pilot study evaluating the Pediatric Urinary Microbiome

A bladder microbiome (urobiome) exists in adults. Data supports the effects of the adult urobiome on urinary tract health with associations between dysbiotic urobiomes and lower urinary tract disorders. Understanding urobiome origin is important since other microbiomes establish around birth and microbiome alterations are linked to disease development. However, the pediatric urobiome has not been well studied. We sought to determine the age when the urobiome develops, compare the pediatric urobiome to microbiomes of adjacent urogenital niches, and compare the urobiomes between boys and girls and across age groups. Seventy-four children less than 18 years of age without recent antibiotic exposure were recruited, including 48 males and 26 females, aged 2 weeks to 209 months of age. Transurethral catheterized urine samples and samples from the perineum, urethra, vagina, and foreskin were collected. Specimens were assessed using the expanded quantitative urine culture protocol and by 16S rRNA gene sequencing. Dada2 was used to profile microbial compositions, and BLCA was used to identify microbial taxa. Bacteria were detected in 90.5% of urine samples and identified in children as young as 2 weeks of age. Microbial communities and compositions of the female bladder and other urogenital niches (urethra, perineum, and vagina) differed significantly by age. Lactobacillus predominated the bladder, urethral, and vaginal microbiomes in post-pubertal girls. Compared to female urinary microbiomes, those of males differed less substantially. Only perineal microbiomes differed significantly by age, whereas male urethral and foreskin microbiomes did not differ significantly. We identified that a urinary microbiome is established as early as infancy. In addition, the female urobiome changes throughout childhood, until the post-pubertal bacterial taxa becomes consistent with that seen in adult females. Whereas in boys, the urinary microbiome changed very little over time. In addition, the surrounding urogenital microbiomes differed less in boys as compared to females. Microbiomes established at a young age may have long-term influences on immune, metabolic, and neurobehavioral traits. The same may be true for the urobiome. Our study provides a foundation for future research to determine the influence of the pediatric urobiome on the development of urinary and even non-urinary disorders. A pediatric urobiome exists, with differences between males and females and can be detected at a young age with changes occurring throughout childhood. Similarities and differences are also seen between the pediatric urobiome and adjacent niches.

Antimicrobial Therapy in Pediatric Sepsis: What Is the Best Strategy?

Pediatric sepsis is a relevant cause of morbidity and mortality in this age group. Children are affected differently in high and low-income countries. Antibiotics are crucial for the treatment of sepsis, but indiscriminate use can increase resistance worldwide. The choice of a correct empiric therapy takes into consideration the site of infection, local epidemiology, host comorbidities and recent antibiotic exposure. Antibiotics should be administered in the first hour for patients with septic shock, and always intravenously or via intraosseous access. Culture results and clinical improvement will guide de-escalation and length of treatment. New diagnostic methods can help improve the prescription of adequate treatment. Prevention of sepsis includes vaccination and prevention of healthcare-associated infections. More research and education for awareness of sepsis is needed to improve care.

Association of Exposure to High-risk Antibiotics in Acute Care Hospitals With Multidrug-Resistant Organism Burden in Nursing Homes

Little is known about the contribution of hospital antibiotic prescribing to multidrug-resistant organism (MDRO) burden in nursing homes (NHs). To characterize antibiotic exposures across the NH patient's health care continuum (preceding health care exposure and NH stay) and to investigate whether recent antibiotic exposure is associated with MDRO colonization and room environment contamination at NH study enrollment. This is a secondary analysis of a prospective cohort study (conducted from 2013-2016) that enrolled NH patients and followed them up for as long as 6 months. The study was conducted in 6 NHs in Michigan among NH patients who were enrolled within 14 days of admission. Clinical metadata abstraction, multi-anatomical site screening, and room environment surveillance for MDROs were conducted at each study visit. Data were analyzed between May 2019 and November 2021. Antibiotic data were abstracted from NH electronic medical records by trained research staff and characterized by class, route, indication, location of therapy initiation, risk for Clostridioides difficile infection (C diffogenic agents), and 2019 World Health Organization Access, Watch, and Reserve (AWARE) antibiotic stewardship framework categories. The primary outcomes were MDRO colonization and MDRO room environment contamination at NH study enrollment, measured using standard microbiology methods. Multivariable logistic regression was used to identify whether antibiotic exposure within 60 days was associated with MDRO burden at NH study enrollment. Additionally, antibiotic exposure data were characterized using descriptive statistics. A total of 642 patients were included (mean [SD] age, 74.7 [12.2] years; 369 [57.5%] women; 402 [62.6%] White; median [IQR] NH days to enrollment, 6.0 [3.0-7.0]). Of these, 422 (65.7%) received 1191 antibiotic exposures: 368 (57.3%) received 971 hospital-associated prescriptions, and 119 (18.5%) received 198 NH-associated prescriptions. Overall, 283 patients (44.1%) received at least 1 C diffogenic agent, and 322 (50.2%) received at least 1 high-risk WHO AWARE antibiotic (watch or reserve agent). More than half of NH patients (364 [56.7%]) and room environments (437 [68.1%]) had MDRO-positive results at enrollment. In multivariable analysis, recent antibiotic exposure was positively associated with baseline MDRO colonization (odds ratio [OR], 1.70; 95% CI, 1.22-2.38) and MDRO environmental contamination (OR, 1.67; 95% CI, 1.17-2.39). Exploratory stratification by C diffogenic agent exposure increased the effect size (MDRO colonization: OR, 1.99; 95% CI, 1.33-2.96; MDRO environmental contamination: OR, 1.86; 95% CI, 1.24-2.79). Likewise, exploratory stratification by exposure to high-risk WHO AWARE antibiotics increased the effect size (MDRO colonization: OR, 2.32; 95% CI, 1.61-3.36; MDRO environmental contamination: OR, 1.86; 95% CI, 1.26-2.75). The findings of this study suggest that high-risk, hospital-based antibiotics are a potentially high-value target to reduce MDROs in postacute care NHs. This study underscores the potential utility of integrated hospital and NH stewardship programming on regional MDRO epidemiology.

P708 Ileal involvement defined by Montreal classification in Crohn’s disease is associated with a distinct microbial composition in ileal and colonic mucosa

Abstract Background The Montreal classification of inflammatory bowel disease (IBD) recognizes distinct subgroups based on location of disease, age at onset and behaviour for Crohn’s disease (CD) and extent in ulcerative colitis (UC). CD with ileal involvement is in part genetically determined and tends to progress to surgery and to be more refractory to medical therapy compared to colonic disease location. We investigated the association of different aspects of the Montreal classification with the ileal and colonic mucosa-associated microbiota. Methods Healthy control (HC) and IBD patients underwent colonoscopy with biopsy samples taken from terminal ileum, ascending and sigmoid colon. Mucosal 16s rRNA gene profiling was analysed and an amplicon sequence variant table was generated and normalized. Patients with prior intestinal resection, IBD-unclassified and recent antibiotic exposure were excluded. Endoscopic activity was defined as a segmental Mayo endoscopic subscore &amp;gt; 0 in UC and a simple endoscopic score &amp;gt; 2 in CD. Blood samples were drawn for genotyping and a weighted genetic risk score (GRS) was built based on 169 IBD risk variants. Pooled ileal and colonic samples were analysed for taxonomic differential abundance (DA) among the variables of the Montreal classification using a linear mixed-effects model (MaAsLin2) with age, sex, biopsy site, endoscopic activity and GRS as covariates. P-values were corrected for false discovery rate (FDR) and &amp;lt; 5% was considered significant. Results A total of 546 biopsy samples from 201 IBD patients and 48 HC were analysed. The characteristics of the cohort and Montreal classification are depicted in the Table. At colonoscopy 168 samples (31.4%) showed endoscopic activity. The multivariate analysis revealed that the genera Agathobacter and Faecalibacterium, as well as the family Ruminococacceae and the order Oscillospirales were significantly reduced in CD with ileal involvement (L1+L3) when compared to either isolated colonic CD (L2), UC (any extent) and HC independent of age, sex, endoscopic activity, biopsy site, and GRS (Figure). Samples from UC and isolated colonic CD patients did not show differences in their microbial profile irrespective of biopsy site. No differences in DA were observed in subgroups based on age at onset and disease behaviour in CD or extent in UC. GRS was not associated with microbial composition. Conclusion These data suggest that CD with ileal involvement (Montreal L1+L3) is a major determinant of the tissue-associated microbial composition in both ileal and colonic mucosa irrespective of variables such as endoscopic activity and GRS. The reduction of several beneficial microbes in CD with ileal involvement might partially explain the more progressive phenotype in such patients.