bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-1479. Patterns of surgical antibiotic prophylaxis among patients undergoing Cesarean deliveries in tertiary care hospitals in Bangladesh
Authors: Dostogir Harun Md Golam , Sumon Md Shariful Amin , Qadri Firdausi , Ghosh Robir Kumar , Rahman Aninda , Md Abdullah Syed Abul Hassan , Islam Md Saiful , Weiser Thomas G , Oakley Lisa P , Styczynski Ashley R , Kaydos-Daniels S Cornelia 
Published: January 2025

Abstract

Background
The World Health Organization recommends a single dose of a first-generation cephalosporin given 30-60 minutes prior to surgery to prevent surgical site infections (SSI) in Cesarean deliveries (C-section). Perinatal exposure to antibiotics may modulate the microbiome of mothers and newborns, favoring the persistence of drug-resistant organisms which are frequently implicated in neonatal sepsis. This study investigated the pattern of surgical antibiotic prophylaxis (SAP) among patients undergoing C-sections in Bangladeshi tertiary care hospitals
Commonly prescribed antibiotics to surgery patients

Commonly prescribed antibiotics to surgery patients

Methods
From May through December 2023, we conducted a prospective observational study in six tertiary care hospitals and enrolled 1,335 women who underwent C-sections. Information on demographics and types of prophylactic antibiotic use was collected during the preoperative, postoperative, and post-discharge phases

Results
The median age of enrolled participants was 26 years (IQR: 22-28) and nearly half (48.9%) had a prior C-section. Pre-operatively, ceftriaxone was the most common SAP, which was used in 88% of cases. The median time for pre-operative antibiotic administration until incision was 180 minutes (IQR: 90-270). Post-operatively, injectable antibiotics were administered to all patients, with ceftriaxone (92.6%) and metronidazole (95.3%) being the most frequently prescribed. Similarly, all patients received oral antibiotics upon discharge. Cefixime (84.6%) and metronidazole (51.0%) were the most prescribed antibiotics at hospital discharge, followed by flucloxacillin (48.4%) and amoxicillin-clavulanic acid (13.1%), for a median duration of 5 days

Conclusion
Patients undergoing C-sections were frequently prescribed broad-spectrum antibiotics as part of SAP with extended post-operative dosing. Extensive SAP use may suggest underlying concerns regarding patient population, local antimicrobial resistance profiles, infection prevention lapses, and a lack of local hospital-based SAP guidelines. Understanding motivations for and effects of SAP patterns is essential for mitigating unnecessary perinatal antibiotic exposure and guiding antimicrobial stewardship efforts. Additionally, the timing of pre-operative SAP administration warrants further optimization

Disclosures
All Authors: No reported disclosures
P-1482. Ceftazidime-Avibactam for Treating Bacteremic and Non-Bacteremic Carbapenemase-Producing Enterobacterales Infections in Immunocompromised Patients
Authors: Herrera Fabián , Leone María V , Torres Diego , Rojas Rocío , Bues Florencia , Rearte Andrés N , Temporiti Elena , Querci Marcia , Carlos Jimena , Nicola Federico , Relloso Silvia , Smayevsky Jorgelina , Bonvehi Pablo E 
Published: January 2025

Abstract

Background
Ceftazidime-avibactam (CA) and CA plus aztreonam (ATM) are the preferred treatment options for KPC and metallo-beta-lactamase (MBL) carbapenemase-producing Enterobacterales infections (KPC-CPE and MBL-CPE), respectively. There are not many studies in immunocompromised patients (IP).

Methods
Observational and prospective cohort study. All episodes of KPC-CPE and MBL-CPE infections in IP admitted to a university hospital from August 2018 to April 2023, who received definitive antibiotic therapy (DAT) with CA or CA+ATM for at least 48 hours, were included. Non-bacteremic episodes (NBE) were compared with those with bacteremia (BE). Logistic regression analysis was performed to identify risk factors for 30-day mortality (RFM).

Results
Seventy-six episodes were included (36 NBE and 40 BE). Hematological malignancies and neutropenia were more frequent in BE (NBE 13.9% vs. BE 50.2%, p&lt; 0.001; and NBE 5.6% vs. BE 42.5%, p&lt; 0.001), while solid organ transplantation was in NBE (NBE 66.7% vs. BE 32.5%, p=0.003). The urinary source was more frequent in NBE (NBE 72.2% vs. BE 30%, p&lt; 0.001), while the abdominal source was in BE (NBE 2.8% vs. BE 17.5%, p=0.04). K. pneumoniae was the main isolated microorganism, and KPC-CPE was the most common resistance mechanism in both groups, followed by MBL-CPE, without significant differences. Septic shock at onset was higher in BE (NBE 8.3% vs. BE 30%, p=0.18). Empirical treatment was appropriate in 59.3% of NBE vs. 75% of BE, p=0.12. Seven-day mortality, 30-day overall and infection-related mortality in NBE and BE were 2.8% vs. 5%, p=0.40; 11.1% vs. 27.5%, p=0.07; and 0% vs. 10%, p=0.07; respectively. The RFM were APACHE II score &gt;20 [OR 5.80 (95% CI 1.19-28.17)], and acute renal failure [OR 16.15 (95% CI 1.78-146)].

Conclusion
KPC-CPE and MBL-CPE infections in IP with or without bacteremia who received DAT with CA or CA+ATM had low early and 30-day infection-related mortality. RFM were related to the severity and complications of the infections.

Disclosures
Diego Torres, Medical Doctor, Gador: Honoraria|GSK: Advisor/Consultant|Khight Therapeutics: Honoraria|MSD: Honoraria
P-1483. Clinical Features and Outcomes of KPC and NDM Carbapenemase-Producing Enterobacterales Infection in the Era of Avibactam
Authors: Herrera Fabián , Leone María V , Torres Diego , Rojas Rocío , Bues Florencia , Rearte Andrés N , Temporiti Elena , Querci Marcia , Carlos Jimena , Nicola Federico , Relloso Silvia , Smayevsky Jorgelina , Bonvehi Pablo 
Published: January 2025

Abstract

Background
Carbapenemase-producing Enterobacterales infections (CPEi) often have poor prognosis and high mortality. However, no local studies compare KPC and NDM-CPEi treated with ceftazidime-avibactam (CA) or ceftazidime-avibactam plus aztreonam (CA+ATM).

Methods
Prospective cohort study. We included episodes of KPC and NDM-CPEi in patients admitted to a university hospital (from August 2018 to April 2023) who received definitive antibiotic treatment (AT) with CA or CA+ATM, respectively. We compared clinical characteristics and outcomes with 30-day follow-up. We performed a logistic regression for 30-day mortality analyses.

Results
One hundred and fifty-six episodes of CPEi were included (117 KPC and 39 NDM). Median APACHE II score was 15 (10-21) vs. 16 (10-20.5), p=0.755. Patients were immunocompromised in 53.8% vs. 41%, p=0.165. Bacteremia was present in 47% vs. 59%, p=0.196, and urinary and abdominal were the most frequent clinical sources of infection (44.4% vs. 38.5%, p=0.513; and 9.4% vs 15.4%,p=0.224; respectively). Klebsiella spp. was the main isolate in both groups (75.2% vs. 87.2%, p=0.117). Empirical AT was appropriate in 59.8% vs. 56.4%, p=0.707; and they received empirical CA in 45.3% vs 38.5%, p=0.456. Septic shock occurred in 24.8% vs. 35.9%, p=0.179. Seven and 30-day mortality and infection-related mortality were 3.4% vs. 0%, p=0.312; 13.7% vs. 25.6%,p=0.082; and 4.3% vs. 12.8%, p=0.071. APACHE II &gt;20 [OR 5.9 (95% CI 1.97-17.98), p=0.002], and skin and soft tissue infection [OR 6.02 (95% CI 1.22-29.62), p=0.027] were independently associated with 30-day mortality, while the 7-day clinical response was a protective factor [OR 0.04 (95% CI 0.004-0.405) p=0.006].

Conclusion
In patients with KPC and NDM-CPEi treated with CA or CA+ATM, clinical features and outcomes were similar. Mortality was associated with the severity and the source of infection while the seven-day clinical response was a protective factor. Our data support the role of CA AND CA+ ATM in these types of infections.

Disclosures
Diego Torres, Medical Doctor, Gador: Honoraria|GSK: Advisor/Consultant|Khight Therapeutics: Honoraria|MSD: Honoraria
P-1487. β-tricalcium Phosphate/Calcium Sulfate Loaded with Contezolid Acefosamil (MRX-4) for Antimicrobial Potency, Prevention and Killing Efficacy of MRSA Biofilm
Authors: Jiang Nan , Chen Peng , Wan Haoyang , Liu Guanqiao , Lin Qinrong , Yu Bin 
Published: January 2025

Abstract

Background
The use of local antibiotics loaded by antibiotic carriers represents an important strategy for the treatment of osteoarticular infections. This study evaluated the antimicrobial duration of potency and the prevention and killing efficacies of contezolid acefosamil (MRX-4) against MRSA biofilm in in-vitro assays.Figure 1ZOIs of C+G versus V+G loaded by CS

Methods
The elution kinetics of contezolid acefosamil (C) and vancomycin (V) in combination with gentamicin (G), loaded with either β-tricalcium phosphate/calcium (β-TCP/CS) sulfate or CS, in the presence of an MRSA (ATCC43310) infection was assessed. The efficacies of the agents in preventing biofilm formation and killing pre-formed biofilms were assessed using colony-forming unit count and confocal laser scanning microscopy.Figure 2Changes of ZOIs of C+G versus V+G (a, b) and β-TCP/CS versus CS (c, d)

Results
In a repeated Kirby-Bauer like zone of inhibition (ZOI) assay, V+G showed potency against MRSA for approximately 40 days. While the ZOIs of C+G at 40 days were similar to those at 15 days, which were significantly larger than those of V+G (P &lt; 0.05). In the MRSA biofilm prevention assays, both C+G and V+G showed similar efficacies in preventing bacterial colony formation, with approximately 8 logs lower colony-forming units than those in the control group at 1 and 3 days (P &lt; 0.01). The killing efficacies on pre-formed biofilms showed significant decrease of approximately 3 to 4 logs at 1 and 3 days following treatment with C+G and V+G (P &lt; 0.001). Furthermore, the confocal laser scanning microscopy results supported the colony-forming unit outcomes. Additionally, β-TCP/CS and CS revealed similar antimicrobial potency and prevention and killing efficacies in these in-vitro assays.Figure 3Colony-forming units in the prevention and killing groups(C1:control group 1: blank groups, C2: control group 2: β-TCP/CS or CS beads without antibiotics; ns: not statistically significant, *P ＜ 0.05, **P ＜ 0.01, ***P ＜ 0.001 )

Conclusion
The present study demonstrated that contezolid acefosamil displays similar prevention and killing efficacies against MRSA biofilms in comparison to vancomycin. However, the antimicrobial duration of potency of contezolid acefosamil is longer than vancomycin. Further clinical trials are required to determine whether contezolid acefosamil can be locally applied for the treatment of osteoarticular infections.

Disclosures
All Authors: No reported disclosures
P-1488. Clinical Efficacy of Minocycline in the Treatment of Carbapenem-resistant Acinetobacter baumannii Pneumonia
Authors: Seok Hyeri , Kim Si-Ho , Shi Hye Jin , Huh Kyungmin 
Published: January 2025

Abstract

Background
Minocycline is one of the few antibiotics that remain active against carbapenem-resistant Acinetobacter baumannii (CRAB). However, the efficacy of minocycline in CRAB pneumonia has not been clearly demonstrated.

Methods
We conducted a multicenter retrospective cohort study at three university-affiliated teaching hospitals in patients with CRAB pneumonia who were admitted between October 2017 and October 2022. Patients were divided into two groups depending on whether minocycline was included in the antibiotics treatment regimen. Propensity scores for minocycline use were calculated using logistic regression, and logistic regression with overlap weighting was conducted to assess whether there were significant differences in outcome variables and safety variables between the two groups.

Results
We enrolled 430 CRAB pneumonia patients, among which 201 patients were treated with minocycline and 229 patients without minocycline. Intensive care unit stay was more frequent (77.6% vs 65.1%, P value = 0.006) and serum creatinine was higher (0.9 vs 0.8 mg/dL, P = 0.023) in the minocycline group than in the non-minocycline group. Variables associated with minocycline use in logistic regression were cerebrovascular disease (odds ratio [OR] 4.51, 95% confidence interval [CI] 2.07–9.85, P &lt; 0.001), higher serum creatinine (OR 1.37, 95% CI 1.01–1.87, P = 0.046), and combination antibiotic regimen (OR 124.73, 95% CI 43.23–359.84, P &lt; 0.001). Bacteremia (OR 0.19, 95% CI 0.05–0.73, P = 0.016) and lower Charlson comorbidity index (CCI) (OR 0.76, 95% CI 0.64–0.91, P = 0.003) were inversely associated with minocycline use. The clinical success rate on day 14 was higher in the minocycline-treated group (58.3% vs 41.7%, P &lt; 0.001). In the adjusted model, the use of minocycline was significantly associated with clinical success (adjusted OR [aOR] 3.88, 95% CI 1.55–9.70, P = 0.004), lower 28-day mortality (aOR 0.28, 95% CI 0.10–0.79, P = 0.016), and a longer mechanical ventilator-free day (4.51 days longer, 95% CI 2.64–6.37, P &lt; 0.001).

Conclusion
Minocycline, when used as a combination treatment in the treatment of CRAB pneumonia, showed superior results in terms of 14-day clinical success and 28-day mortality. Minocycline may be considered one of the antibiotic treatment options for CRAB pneumonia.

Disclosures
Kyungmin Huh, M.D., Ph.D., bioMérieux: Grant/Research Support|GSK Korea: Advisor/Consultant|Pfizer Korea: Honoraria|Takeda Korea: Advisor/Consultant
P-1489. Shaken Not Stirred: Novel Antibiotic Cocktails to Combat Pan-Drug Resistant Klebsiella pneumoniae
Authors: Kaur Jan Naseer , Chen Albert , Hanna Allison , Klem Jack F , Holden Patricia N , Chen Liang , Smith Nicholas M , Tsuji Brian T 
Published: January 2025

Abstract

Background
K. pneumoniae producing Metallo-Beta-Lactamases (MBL) confers resistance to a large spectrum of beta-lactam antibiotics which is a cause for significant concern. Novel combinatorial therapies can be an effective option for treating MBL Gram-negatives. The present study assessed the synergistic potential of Polymyxin B combinatorial strategies to combat the rising tide of PDR Gram-negative strains which have emerged worldwide.

Methods
K. pneumoniae producing blaNDM-5, blaCTX-M-55 and mcr-1 was exposed to an array of therapeutic regimens in a Hollow Fiber Infection Model (HFIM) over 9 days. These regimen arms included Polymyxin B (fCss = 4 mg/L), Aztreonam (fCss = 21 mg/L) + Avibactam (fCss = 5.5 mg/L), Aztreonam (fCss = 21 mg/L) + Avibactam (fCss = 5.5 mg/L) + Polymyxin B (fCss = 4 mg/L). Bacterial plate counts were taken throughout the experiment. Samples were also fixed and imaged under a Scanning Electron Microscope.

Results
Closely mirroring the growth control, Polymyxin B monotherapy did not inhibit the growth of K. pneumoniae S200. The clinical combination of aztreonam + avibactam demonstrated initial bactericidal activity with 6 log fold reduction (total count 1.6 log10 CFU/mL) over 24h followed by rapid recovery as the counts bounced back to 6.07 log10 CFU/mL by 48h. Reversion experiments demonstrated complete regrowth to 9.53 log10 CFU/mL by the 216h time point. In contrast, the addition of polymyxin B to the β-lactam/β-lactamase inhibitor combination resulted in prolonged marked bactericidal activity with 6.05 log fold reduction within 24h and eventually below the detectable limits over 168h.This was supported by tracking the evolution of salient phenotypic alterations using SEMs over 216h that showed filamentation in response to aztreonam containing regimens and lack of viable cells as well as overwhelming presence of cellular debris in Polymyxin B combination arm at 24 and 168h.

Conclusion
The results of the present study suggest that despite the intrinsic mcr-1 and blaNDM-5 resistance mechanisms our novel antibiotic cocktails show significant promise. Novel therapeutic options that enhance combinatorial pharmacodynamics are necessary to combat the urgent threat of MBL Gram-negative strains which are resistant to all antibiotics.

Disclosures
All Authors: No reported disclosures
P-1496. Retrospective Study of Ceftazidime-Avibactam Treatment for Multidrug-Resistant Gram-Negative Bacterial Infections in King Chulalongkorn Memorial Hospital
Authors: Jutivorakool Kamonwan , Reinprayoon Rongpong 
Published: January 2025

Abstract

Background
Antimicrobial resistance, particularly among Enterobacterales, poses a significant healthcare threat. With the rise of carbapenem-resistant strains, alternative treatment strategies are necessary. This study explores the clinical experience of using ceftazidime-avibactam (CAZ-AVI) in treating infections caused by multidrug-resistant Gram-negative bacteria (MDR-GNB), including carbapenem-resistant pathogens.Table 1.Baseline characteristics of the patients who received CAZ/AVI

Methods
A single-center retrospective observational study was conducted at King Chulalongkorn Memorial Hospital, Thailand, from Jan. 2019 to Dec. 2022. The study included adult patients aged ≥18 years, who receiving ≥48 hours of CAZ-AVI for documented MDR-GNB infections. Data on demographics, comorbidities, treatment regimens, and outcomes were extracted from electronic medical records. The primary outcome was all-cause mortality at 14 days. Secondary objectives included clinical and microbiological responses at 14 days, and all-cause mortality at 28 days.Table 2.Clinical outcomes of the patients who received CAZ/AVI

Results
Among 85 patients receiving CAZ-AVI, 75 met inclusion criteria. The mean age was 65.27 years, with 54.7% being male. Hospital-acquired infections accounted for 82.7%, and 56% were ICU patients. Underlying conditions included chronic kidney diseases/end-stage renal diseases (28%), solid tumors (24%), cirrhosis (13.3%), hematologic malignancies (10.7%), and solid organ transplantation (10.7%). K. pneumoniae was the most common organism (69.3%), followed by P. aeruginosa (20%). All (100%) of K. pneumoniae and E. coli were carbapenem resistance. CAZ-AVI susceptibility was observed in 93.6% of isolates. The 14-day all-cause mortality rate was 25.3%. Clinical and microbiological response rates were 70.7% and 65.3%, respectively. Infection by CAZ-AVI-susceptible organisms correlated with lower mortality rates (p=0.017). No adverse drug effects were reported.Table 3.Clinical outcomes of the patients who received CAZ/AVI

Conclusion
This study highlights the promising role of CAZ-AVI in treating MDR-GNB infections, offering an alternative to conventional therapies. While challenges remain, including the complexity of empirical therapy and variations in patient outcomes, CAZ-AVI demonstrates efficacy with a favorable safety profile.

Disclosures
KAMONWAN JUTIVORAKOOL, MD, Msc, Pfizer, Thailand: Grant/Research Support|Pfizer, Thailand: Honoraria Rongpong Reinprayoon, MD, MSc, Pfizer: Grant/Research Support
P-1498. Contezolid is Active against Methicillin-Resistant Staphylococcus aureus in Experimental Rat Foreign Body Osteomyelitis
Authors: Karau Melissa J , Herren Sebastian , Koscianski Christina , Greenwood-Quaintance Kerryl , Mandrekar Jay , Patel Robin 
Published: January 2025

Abstract

Background
Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of orthopedic implant-associated infection, where S. aureus can survive intracellularly and form biofilms. Vancomycin has poor activity against staphyloccoccal biofilms. Although rifampin is effective against staphylococcoal biofilms and has intracellular activity, resistance may develop when it is used as a single agent. Contezolid is a novel oxazolidinone with reported activity against S. aureus in vitro and in vivo in both murine systemic and thigh infection models. Here, we assessed the in vivo activity of contezolid, with and without rifampin, in a rat model of foreign body osteomyelitis.
Figure 1.
Quantities of MRSA IDRL-6169 recovered from A. tibia B. K-wire. Circles represent values from individual animals; horizontal lines represent mean values. Compared to no treatment: *p=0.0186 **p&lt;0.0002

Methods
The left tibia of 60 male Wister rats were inoculated with arachidonic acid (sclerosing agent) and 106 cfu MRSA IDRL-6169 and a K-wire implanted. After four weeks, rats received either no treatment, contezolid (50 mg/kg orally, every 12 h), rifampin (10 mg/kg intraperitoneally every 12 h), rifampin plus contezolid, or vancomycin (75 mg/kg intraperitoneally, every 12 h) plus rifampin for 21 days. Following treatment, tibiae were harvested and cyropulverized. Tibiae and K-wires were cultured separately, and results reported as log10 cfu/gram of bone or K-wire (limit of detect 0.1 log10), respectively. Wilcoxon rank-sum test and false discovery rates were performed and p&lt; 0.05 considered significant.

Results
Results are shown in Figure 1. MRSA was recovered from tibiae and K-wires of all untreated animals, at means of 5.1 log10 cfu/bone and 3.0 log10 cfu/K-wire, respectively. There was a 1.0 log10 cfu/g mean reduction in MRSA recovered from the tibiae of contezolid-treated rats compared to untreated rats (p=0.0186), and a 0.2 log10 reduction on K-wires. No MRSA was recovered from the tibiae or K-wires in animals receiving rifampin, whether alone or in combination with contezolid or vancomycin.

Conclusion
Contezolid was active against MRSA in a rat model of foreign body osteomyelitis, reducing bacterial loads in bone, albeit not on K-wires, unless co-administered with rifampin.

Disclosures
Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria