Multidrug-resistant Organisms Research Articles

Microbial Trends and their Drug Resistance Responsible for Bloodstream Infections in a Superspeciality Transplant Hospital

Background & Objective: Bloodstream infections (BSIs) are critical healthcare-associated infections that lead to high morbidity and mortality, requiring rapid diagnosis and effective antimicrobial treatment. The increasing prevalence of multidrug-resistant organisms (MDROs) exacerbates this issue, particularly in developing countries. The purpose of this study is to assess the bacteriological profile and antimicrobial susceptibility trends of BSIs to establish an antibiogram for effective empirical treatment. Materials and Methods: This study was conducted retrospectively on 3,300 blood culture samples from a multispecialty hospital over 15 months. Cultures were performed using Bactec FX and identification and antibiotic susceptibility determined by Vitek2 and Kirby-Bauer methods following CLSI guidelines. Results: Overall, the positivity rate was (14.3%) with 473 isolates: (400 bacterial and 73 fungal). Gram-negative bacteria were predominant, led by Klebsiella pneumoniae (113 isolates) and Escherichia coli (100 isolates). Among the Gram-negative bacteria, antimicrobial susceptibility was found to be low for Cephalosporins (21%sensitivity) and Fluoroquinolones (19.3% sensitivity), with moderate susceptibility to Carbapenems (51.3%). Sensitivity was high for Colistin (98.9%), Amikacin (91.05%), Tigecycline (100%), Fosfomycin (100%) and Ceftazidime-avibactum Aztreonam (97.7%). Among Gram-positive bacteria, Coagulase-negative Staphylococcal Species (CONS) and Staphylococcus aureus were the most common. The overall sensitivity of Gram-positive bacteria to antibiotics tested was high compared to the Gram-negative bacteria. Sensitivity to antibiotics such as Linezolid was found to be 94.5% and Vancomycin was found to be 93.5%. Conclusion: The high incidence of MDROs especially among the Gram-negative bacteria highlights the need for continuous monitoring and antibiotic stewardship programs. Empirical therapy must consider local resistance patterns, and a multidisciplinary approach is essential to mitigate antimicrobial resistance.

Transmission of MRSA, ESBL E. coli, and C. difficile within a tertiary care hospital and across surrounding facilities in Japan: a molecular epidemiological study with the PCR-based Open-reading frame typing.

To determine the regional impact of transmission of multidrug-resistant organisms (MRDOs) and Clostridioides difficile (C. difficile) among a tertiary care hospital and surrounding facilities including long-term care facilities (LTCFs). Retrospective cohort study. Patients admitted to a tertiary care hospital from July 2019 to July 2021 were recruited if their clinically collected cultures grew the following pathogens: Methicillin-resistant Staphylococcus aureus (MRSA), Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacterales, Pseudomonas aeruginosa with difficult-to-treat resistance, Carbapenem-resistant Enterobaterales, Vancomycin-resistant Enterococci, and C. difficile. Patient characteristics including admission and discharge pathway were collected. For the isolates of MRSA, ESBL-producing Escherichia coli (E. coli), and C. difficile, a molecular epidemiological analysis was conducted, utilizing the PCR-based Open-Reading Frame Typing (POT) method. Three hundred-five patients were identified with a total of 332 culture specimens of the target pathogens. The top three were 132 MRSA isolates (43.3%, out of 305), 97 ESBL E. coli (31.8%), and 32 ESBL Enterobacterales (non-E. coli) (10.5%). The target pathogens were more detectable within 3 days among patients admitted from LTCFs or other hospitals than those admitted from home (Odds Ratio 4.6, 95% confidence interval 2.8-7.6, p-value < 0.001). The molecular epidemiological analysis suggested the transmissions of MRSA, ESBL E. coli and C. difficile occurred 52 out of 111 patients within the in-hospital environment, and 7 out of 128 within the prehospital environment, respectively. MDROs/C. difficile transmission is prevalent within a tertiary care hospital and further complicated by its inter-facility transmission across surrounding LTCFs and hospitals in Japan.

Longitudinal genomic surveillance of a UK intensive care unit shows a lack of patient colonisation by multi-drug-resistant Gram-negative bacterial pathogens.

Vulnerable patients in an intensive care unit (ICU) setting are at high risk of infection from bacteria including gut-colonising Escherichia coli and Klebsiella species. Complex ICU procedures often depend on successful antimicrobial treatment, underscoring the importance of understanding the extent of patient colonisation by multi-drug-resistant organisms (MDROs) in large UK ICUs. Previous work on ICUs globally uncovered high rates of colonisation by transmission of MDROs, but the situation in UK ICUs is less understood. Here, we investigated the diversity and antibiotic resistance gene (ARG) carriage of bacteria present in one of the largest UK ICUs at the Queen Elizabeth Hospital Birmingham (QEHB), focusing primarily on E. coli as both a widespread commensal and a globally disseminated multi-drug-resistant pathogen. Samples were taken during highly restrictive coronavirus disease 2019 (COVID-19) control measures from May to December 2021. Whole-genome and metagenomic sequencing were used to detect and report strain-level colonisation of patients, focusing on E. coli sequence types (STs), their colonisation dynamics and antimicrobial resistance gene carriage. We found a lack of multi-drug resistance (MDR) in the QEHB. Only one carbapenemase-producing organism was isolated, a Citrobacter carrying bla KPC-2. There was no evidence supporting the spread of this strain, and there was little evidence overall of nosocomial acquisition or circulation of colonising E. coli. Whilst 22 different E. coli STs were identified, only 1 strain of the pandemic ST131 lineage was isolated. This ST131 strain was non-MDR and was found to be a clade A strain, associated with low levels of antibiotic resistance. Overall, the QEHB ICU had very low levels of pandemic or MDR strains, a result that may be influenced in part by the strict COVID-19 control measures in place at the time. Employing some of these infection prevention and control measures where reasonable in all ICUs might therefore assist in maintaining low levels of nosocomial MDR.

Contextual barriers to infection prevention and control program implementation in hospitals in Latin America: a mixed methods evaluation

BackgroundInfection prevention and control (IPC) programs are essential to prevent and control the spread of multidrug-resistant organisms in healthcare facilities (HCFs). The current implementation of these programs in Latin America remains largely unknown.MethodsWe conducted a mixed-methods evaluation of IPC program implementation in HCFs from Guatemala, Panama, Ecuador, and Argentina, March-July 2022. We used the World Health Organization (WHO) IPC Assessment Framework (IPCAF) survey, a previously validated structured questionnaire with an associated scoring system that evaluates the eight core components of IPC (IPC program; IPC guidelines; IPC education and training; healthcare-associated infection [HAI] surveillance; multimodal strategies; monitoring and audit of IPC practices and feedback; workload, staffing, and bed occupancy; and the built environment and materials and equipment for IPC). Each section generates a score 0–100. According to the final score, the HCF IPC program implementation is categorized into four levels: inadequate (0–200), basic (201–400), intermediate (401–600), or advanced (601–800). Additionally, we conducted semi-structured interviews among IPC personnel and microbiologists using the Systems Engineering Initiative for Patient Safety model to evaluate barriers and facilitators for IPC program implementation. We performed directed content analysis of interview transcripts to identify themes that focused on barriers and facilitators of IPC program implementation which are summarized descriptively.ResultsThirty-seven HCFs (15 for-profit and 22 non-profit) completed the IPCAF survey. The overall median score was 614 (IQR 569, 693) which corresponded to an “advanced” level of IPC implementation (32% [7/22] non-profit vs. 93% [14/15] for-profit HCFs in this category). The lowest scores were in workload, staffing and bed occupancy followed by IPC training and multimodal strategies. Forty individuals from 16 HCFs were interviewed. They perceived inadequate staffing and technical resources, limited leadership support, and cultural determinants as major barriers to effective IPC guideline implementation, while external accreditation and technical support from public health authorities were perceived as facilitators.ConclusionsEfforts to strengthen IPC activities in Latin American HCFs should focus on improving support from hospital leadership and public health authorities to ensure better resource allocation, promoting safety culture, and improving training in quality improvement.

Microbial profile of burn wound injuries in the Northern West Bank − A retrospective cohort study

BackgroundDetermining frequently colonizing microorganisms and typical demographics affected by burns in the West Bank is essential to aid timely and effective injury management. MethodsThis study included n = 435 patients with burn injuries between January 2018-December 2021 at a tertiary center in Nablus. Eligible medical records were reviewed, and relevant data extracted. Resultsn = 244 males and n = 191 females, average age 14.5 years were included. n = 227 had wound swab cultures, n = 80 which were positive. Scald injuries were the most common mechanism of injury (n = 314, n = 162 in males (p < 0.001), average age of 10.5 years). The most common organisms isolated were Pseudomonas aeruginosa (n = 17) and Staphylococcus aureus (n = 18). n = 17 multidrug resistant (MDR) organisms were cultured, MRSA most commonly (n = 9), followed by K. pneumoniae (ESBL) (n = 5). Overall length of stay (LOS) was 17.27 days in all patients and 28.2 days in those with MDR, with increasing LOS significantly associated with positive culture and MDR development of MDR (p < 0.001). ConclusionsYounger male demographics and longer hospital admission increase the risk of burn wound colonization and MDR development in the Northern West Bank. Pseudomonas aeruginosa and Staphylococcus aureus were prevalent organisms isolated. MDR development represents a significant challenge in the effective management of injuries in an immunologically vulnerable cohort.

Surveillance of carbapenem resistance in Asian countries: a systematic review and meta-analysis

IntroductionCarbapenems are used to treat multidrug-resistant organisms as last-resort antibiotics. Resistance to carbapenems is an emerging public health threat worldwide, with alarming reported rates in Asian countries. To minimise further spread of resistant strains and guide interventions, it is important to understand the prevalence rates and causative molecular determinants. Therefore, the systematic review and meta-analysis arising from this protocol will aim to comprehensively describe the available surveillance data on carbapenem resistance in Asian countries to provide an in-depth overview of the carbapenem resistance status in this region.Methodology and analysisA systematic review and meta-analysis will be conducted via PubMed, ScienceDirect, Cochrane Library and Web of Science databases. Additional articles and grey literature will be searched in Google Scholar, OpenGrey and Google Chrome by manually searching the reference lists of selected studies. The review question was designed according to components in the ECLIPSE (E-expectations, C-client, L-location, I-impact, P-profile and S-service) framework. Studies conducted with samples other than clinical samples will be excluded. Only original articles published in the English language will be included. The Joanna Briggs Institute critical appraisal tool will be used to assess the quality of the included studies. A random-effects meta-analysis will be performed if the data are sufficiently homogenous. Heterogeneity between studies will be assessed via the I² statistic. The subgroup analysis will be performed considering the type of sample, pathogen type, region/country where the studies were conducted and genetic determinants.Ethics and disseminationAs this study is conducted on the basis of published data, ethical approval is exempt. The findings of this study will be disseminated in a peer-reviewed journal with the intention of providing summarised data on the globally emerging threat of carbapenem resistance and emphasising the need to introduce alternative, more effective treatment options.PROSPERO registration numberCRD42024515806.

Home-based nursing care for clients carrying multidrug-resistant organisms: a focus group study

Abstract Background The growing population of vulnerable clients receiving home-based nursing care, combined with the worldwide increase in the prevalence of multidrug-resistant organisms (MDROs), poses a new burden on nursing staff. This study aimed to gain insight into the experiences, attitudes, perceptions, dilemmas in daily practice and needs of nursing staff providing home-based nursing care for clients carrying MDROs. Methods Seven focus group discussions with home-based nursing staff (N = 34) were performed in the Netherlands between April and July 2022, using a semi-structured, open-ended topic list based on the I-change model and seven domains synthesized by Flottorp et al. Data were analysed using thematic analysis. Results Home-based nursing staff often considered infection prevention and control recommendations inconsistent, unclear or inapplicable in daily practice. Although participants acknowledged the importance of these precaution measures, their proportionality was sometimes questioned. Participants indicated to be influenced by perceptions, knowledge and behaviour of their colleagues and clients. In addition, they frequently experienced untimely, incomplete or inconspicuous information transfers about clients carrying MDROs. Concerns were expressed that clients were often insufficiently informed, debating the roles and responsibilities of involved healthcare professionals in providing and exchanging information. Finally, participants elaborated on the effect of the covid-19 pandemic and expressed the need for organisational support in providing education and sufficient resources regarding MDROs. Conclusions Insights of this study have aided in aligning upcoming MDRO guidelines for home-based nursing care in the Netherlands. Organisational support in expanding knowledge and providing sufficient resources is essential and clarity about roles and responsibilities of involved healthcare professionals regarding information transfer and informing patients is needed. Key messages • Expanding knowledge, sufficient resources and adequate information transfer about MDRO carriage are essential to ultimately prevent transmission and spread of MDROs. • The specific context of home-based nursing care for clients carrying MDROs should be acknowledged in MDRO guidelines.

Home-based nursing care: what do we know about multidrug-resistant organisms in this setting?

Abstract Background The burden and complexity of home-based nursing care have intensified due to earlier discharges from hospitals and patients living longer at home with increasing co-morbidities. This growing population of vulnerable patients, combined with the worldwide increase in the prevalence of multidrug-resistant organisms (MDROs), poses a new burden on home-based nursing staff. Home-based nursing care differs significantly from hospitals and nursing homes, challenging implementation of infection prevention and control (IPC) measures. It is therefore important to gain insight into the attitudes, experiences and needs of home-based nursing staff. Also, to better understand the scope of MDRO carriage and transmission in this setting, including its challenges. Methods Cross-sectional studies were conducted in the Netherlands including a survey and focusgroup study among home-based nursing staff, supplemented by a report of cases of MDRO clusters. Results We have identified several factors adding to the complexity of responding to an MDRO outbreak with involvement of home-based nursing care. First, inapplicable recommendations in guidelines/protocols or from infection preventionists, often aimed at intramural care. Second, nursing staff questioned the proportionality of IPC measures, potentially influenced by behaviour of colleagues and patients. Third, inadequate information transfers about patients carrying MDROs. Fourth, uncertainty about the roles and responsibilities of involved healthcare professionals. Finally, the need for organisational support in providing education and sufficient resources, and clarity about financial aspects. Conclusions Insights from these studies have aided in aligning upcoming MDRO guidelines for home-based nursing care in the Netherlands, which factor in the above mentioned complexity. Furthermore, these findings can aid in future strategies to prevent or respond early in MDRO outbreaks with involvement of home-based nursing care.

4.C. Scientific session: Navigating through complex challenges of responding to outbreaks of multidrug-resistant organisms

Abstract Antimicrobial resistance is one of the top ten global public health threats according to the WHO, contributing to millions of deaths each year. While outbreaks of multidrug-resistant organisms (MDROs) are well studied in hospital and nursing home settings, knowledge gaps exist concerning the complex challenges of outbreaks of MDROs among vulnerable patient populations, such as patients with intellectual disabilities or elderly patients living longer at home with multiple comorbidities. The coordination of such outbreaks requires a multidisciplinary approach as these patients often receive care throughout different healthcare settings, including long-term care and home-based nursing care. We delve into the complexities of coordinating an MDRO outbreak response involving healthcare professionals from various healthcare settings. The challenges inherent to the coordination of multidisciplinary involvement and the use of innovative strategies for outbreak preparedness and surveillance, will be thoroughly examined based on scientific evidence and practice based experiences. Workshop objectives • To exchange experiences on managing cross-institutional outbreaks of MDROs • To foster deeper understanding of the complexities of multidisciplinary involvement during MDRO outbreaks among vulnerable patient populations The workshop structure: - A brief introduction will be provided on the generic challenges in providing long-term care to vulnerable patient populations carrying MDROs. We will subsequently illustrate potential challenges faced during a cross-institutional MDRO outbreak among these patients through a realistic scenario (5 min): A patient with severe intellectual and physical disabilities living in both a long-term care facility as well as with family at home, unexpectedly turns out to be carrying an MDRO after recent hospital admission. As the patient receives nursing care from both from family members and nursing staff in different healthcare settings, a cross-institutional MDRO outbreak has occurred requiring a coordinated response. - Hereafter, individual presenters will address evidence- and experience-based challenges faced in MDRO outbreak responses within the specific healthcare settings covered in the previously presented scenario. We will navigate through the scenario together with the participants, discussing practical and ethical dilemmas, and explore ways for containing the MDRO outbreak while maintaining effective and compassionate healthcare delivery. In addition, we will discuss the use of public health innovations, such as social network analysis as a basis for the development of a stress test exercise to improve preparedness for MDRO outbreaks, and the role of wastewater surveillance in MDRO outbreaks. Discussions will be facilitated by (online) voting tools to invite participants to exchange experiences (40 min). We conclude with an exciting quiz to summarize the key messages of this workshop (10 min). Key messages • Healthcare setting, knowledge, proportionality and well-being of vulnerable patients populations are important to acknowledge during cross-institutional MDRO outbreaks. • Novel stress test exercise and wastewater surveillance are potential methods to improve preparedness and surveillance, respectively, during cross-institutional MDRO outbreak responses.

Long-term care facilities: what do we know about multidrug-resistant organisms in this setting?

Abstract Background People with intellectual disabilities (ID) are an often overlooked high-risk group for health-related issues. In the Netherlands, people with ID may reside at home, in small communities, or within long-term care facilities. This diverse living arrangement challenges the healthcare system, with responsibilities spread among multiple formal and informal caregivers. During an outbreak with multidrug-resistant organisms (MDROs), coordinated efforts should be made to prevent further spread throughout all healthcare settings. Therefore, adequate infection prevention and control (IPC) practices, are required to improve or maintain individual health outcomes. To understand the complexity of MDROs in long-term care for people with ID, it is important to gain insight into knowledge, attitudes and perceptions of involved healthcare professionals and, investigate innovative strategies that could play a role in surveillance or monitoring an outbreak within this setting. Methods We conduct several studies in long-term care for people with ID, using a wide scale of methodologies including a cross-sectional survey study and innovative quantitative methods, such as wastewater surveillance. Results We have identified several challenges in long-term care for people with ID related to IPC and MDROs. First, while IPC and MDRO guidelines exist, they lack specific context and applicability to the long-term care setting. Second, proper use of hand gloves among healthcare professionals demands increased attention as knowledge about this preventive measure seems to be insufficient. Finally, given the challenges in sample collection for MDRO screening, non-invasive strategies are needed to offer insight during outbreaks, serving surveillance or outbreak management purposes. Conclusions Insights from these studies could inform future strategies to prevent or respond early in case of an MDRO outbreak within long-term care for people with ID.

Preparedness for and collaboration during regional outbreaks with multidrug-resistant organisms

Abstract Background Outbreaks with multidrug-resistant organisms (MDROs) are a significant burden on the healthcare system and the wellbeing of affected patients and carriers. Cross-institutional MDRO outbreaks require a concerted multidisciplinary effort for effective outbreak management. This presents challenges regarding cooperation, coordination and communication between stakeholders. In this study, we investigate collaborative structures and coordination roles in Dutch outbreak response networks and how Dutch healthcare professionals engage in preparedness activities relating to MDRO outbreaks. These findings form the basis for the development of a stress test exercise for improving professional and organizational collaboration and coordination during MDRO outbreaks. Methods Using a mixed-methods design, an online survey and qualitative interviews are conducted among healthcare professionals in two healthcare regions in the Netherlands. Social network analysis is used to gain insight in collaborative structures and brokerage roles. To investigate preparedness activities, the survey is combined with qualitative interviews to explore respondents’ experiences, preferences and needs regarding preparedness activities for MDRO outbreak management. Results During the workshop we will show the cross-organizational network structures, the strengths and weakness of the mutual connections and provide insight in positions in networks, roles and responsibilities. Also, we provide insight in how the use of and experience with training and exercise activities, such as stress tests, contribute to preparedness for MDRO outbreaks in vulnerable patient populations. Conclusions This study shows how healthcare professionals from different organizations collaborate during MDRO outbreaks, and how they engage with preparedness activities. This provides valuable input for development of a stress test specific to MDRO outbreak management, and other interventions to improve outbreak preparedness.

Impact of Exogenous Lactiplantibacillus plantarum on the Gut Microbiome of Hematopoietic Stem Cell Transplantation Patients Colonized by Multidrug-Resistant Bacteria: An Observational Study

Background: Lactiplantibacillus plantarum can inhibit the growth of multidrug-resistant organisms (MDROs) and modulate the gut microbiome. However, data on hematopoietic stem cell transplantation (HSCT) are scarce. Aim: In an observational study, we assessed the impact of L. plantarum on the modulation of the gut microbiome in HSCT patients colonized by MDROs. Methods: Participants were allocated to an intervention group (IG = 22) who received capsules of L. plantarum (5 × 109 CFU) twice per day until the onset of neutropenia or a control group (CG = 20). The V4 region of the 16S bacterial rRNA gene was sequenced in 87 stool samples from a subset of 33 patients (IG = 20 and CG = 13). The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) program was used to predict metagenome functions. Results: L. plantarum demonstrated an average 86% (±11%) drug-target engagement at 43 (±29) days of consumption and was deemed safe, well-tolerated, and associated with an increase in the abundance of the Lactobacillales (p &lt; 0.05). A significant increase in Lactococcus and a reduction in Turicibacter (p &lt; 0.05) were identified on the second week of L. plantarum use. Although Enterococcus abundance had a greater rise in the CG (p = 0.07), there were no significant differences concerning the Gram-negative MDROs. No serious adverse effects were reported in the IG. We observed a greater, non-significant pyruvate fermentation to propanoate I (p = 0.193) relative abundance in the IG compared with the CG. L. plantarum use was safe and tolerable by HSCT patients. Conclusions: While L. plantarum is safe and may impact Enterococcus and Turicibacter abundance, it showed no impact on Gram-negative MDRO abundance in HSCT patients.

Resistance Profiles of the ESKAPEE Complex at Veracruz’ s Children Hospital, 2023

Abstract Introduction ESPAKEE complex bacteria are well known as a Multidrug Resistance Organisms that cause difficult mange infections. Management of these infections should be based on the monitoring of resistance profiles to provide appropriate therapy to reduce hospitalization costs and patient improvement. Materials and methods A cross-sectional, retrospective, descriptive study analyzed 179 ESKAPEE bacteria isolated from pediatric patients (0-18 years) between January 1 and December 31, 2023. Laboratory tests utilized VITEK 2.0 technology, reporting Minimal Inhibitory Concentration (MIC) and classifying them as resistant or non-resistant. Descriptive statistics were generated using SPSS v22. Results The study included 179 antibiograms. Among Enterobacter species, E. aerogenes (3) and E. cloacae (17) showed 100% resistance to cefalotin. S. aureus (22) exhibited the highest resistance to Oxacillin (36.4%). Klebsiella pneumoniae (40) demonstrated 97.5% resistance to Ampicillin, followed by resistance to first-generation cephalosporins: cefalotin 62.5%, and third-generation cephalosporins: ceftriaxone and ceftazidime both at 60%. Acinetobacter baumannii (9) showed 100% resistance to Fosfomycin. Pseudomonas aeruginosa (30) displayed 100% resistance to Ceftriaxone, Cefotaxime, and Cefuroxime. Enterococcus faecium (2) exhibited 100% resistance to ciprofloxacin, erythromycin, ampicillin, and levofloxacin, while Enterococcus faecalis (16) showed 50% resistance to tetracycline. E. coli (39) exhibited the highest resistance to Ampicillin (87.2%), while in first-generation cephalosporins: cefalotin 66.7%, third generation: cefotaxime 66.7%, ceftazidime 64.1%, and ceftriaxone 66.7%. Conclusions The ESKAPEE complex species isolated in the hospital displayed diverse resistance profiles against various antibiotic families. Key messages • Monitoring ESKAPEE bacteria’s resistance profiles enables physicians to select appropriate antibiotics at optimal dosages and timings. • Physician should know the rate of resistance of the antibiotics that they use for treatment of ESKAPEE bacteria.

Antimicrobial stewardship program in one primary care hospital, a snapshot analysis

Abstract Antimicrobic resistance (AMR) continues to rise, whereas development of new agents to counter it has slowed. A heightened need to maintain the effectiveness of currently available agents exists. Healthcare-associated infections (HAIs) are a significant cause of poor treatment outcomes and elevated healthcare and societal costs worldwide. At the beginning of 2024, we started a prospective, interventional, interrupted time-series study, based on Prospective Audit and Feedback in the Intensive Care Unit (ICU) and in the internal medicine ward of our hospital. The primary outcomes will be the difference in the antibiotic consumption, and the incidence of bloodstream infections (BSI) caused by multidrug-resistant (MDR) organisms. The secondary outcomes will include the hospital mortality rate, the mean length of stay and the antibiotic expense. We conducted a snapshot analysis of the first three months to assess the efficacy our program. In the first three months we registered a global reduction in antibiotic expense (almost by half in comparison of 2023 first quarter) and consumption, particularly in the use of carbapenems: (change in level, CL: -51,26 DDD/1000 PD,) and third- generation cephalosporins (CL: -6 DDD/1000 PD). We registered a reduction in the use of hydroalcoholic gel, probably due to the reducted perception after the waning of risk perception towards Covid-19, although no big difference was observed in BSI incidence due to MDR Gram-negative organisms (CL: +1,2 events/1000 PD). Albeit partial, once again these findings demonstrated that implementation of an antimicrobial stewardship program, no matter the level of healthcare, is critical for fighting the AMR and to lessen the burden on Public Health; in particular our program induced a significant reduction in antibiotic consumption that lead to more funds at disposal to improve our clinical practice. Key messages • Once again our findings demonstrated that implementation of an antimicrobial stewardship, no matter the level of healthcare, is critical for fighting the AMR. • Our program induced a significant reduction in antibiotic consumption.

The Challenge of Treating Infections Caused by Metallo-β-Lactamase-Producing Gram-Negative Bacteria: A Narrative Review.

Gram-negative multidrug-resistant (MDR) bacteria, including Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa, pose a significant challenge in clinical practice. Infections caused by metallo-β-lactamase (MBL)-producing Gram-negative organisms, in particular, require careful consideration due to their complexity and varied prevalence, given that the microbiological diagnosis of these pathogens is intricate and compounded by challenges in assessing the efficacy of anti-MBL antimicrobials. We discuss both established and new approaches in the treatment of MBL-producing Gram-negative infections, focusing on 3 strategies: colistin; the recently approved combination of aztreonam with avibactam (or with ceftazidime/avibactam); and cefiderocol. Despite its significant activity against various Gram-negative pathogens, the efficacy of colistin is limited by resistance mechanisms, while nephrotoxicity and acute renal injury call for careful dosing and monitoring in clinical practice. Aztreonam combined with avibactam (or with avibactam/ceftazidime if aztreonam plus avibactam is not available) exhibits potent activity against MBL-producing Gram-negative pathogens. Cefiderocol in monotherapy is effective against a wide range of multidrug-resistant organisms, including MBL producers, and favorable clinical outcomes have been observed in various clinical trials and case series. After examining scientific evidence in the management of infections caused by MBL-producing Gram-negative bacteria, we have developed a comprehensive clinical algorithm to guide therapeutic decision making. We recommend reserving colistin as a last-resort option for MDR Gram-negative infections. Cefiderocol and aztreonam/avibactam represent favorable options against MBL-producing pathogens. In the case of P. aeruginosa with MBL-producing enzymes and with difficult-to-treat resistance, cefiderocol is the preferred option. Further research is needed to optimize treatment strategies and minimize resistance.

Analysis of Risk Factors for Multidrug-Resistant Organism (MDRO) Infections and Construction of a Risk Prediction Model in a Cancer Specialty Hospital.

Aims/Background Patients receiving treatment in specialized cancer hospitals are particularly susceptible to multidrug-resistant organisms (MDRO) infections due to factors such as weakened immune systems caused by intensive treatments and prolonged hospital stays. This study aims to investigate the risk factors for MDRO infections in the cancer specialty hospital setting and to develop a corresponding risk prediction model. Methods Patients diagnosed with MDRO infections were selected for the MDRO infection group (n = 238), and those without for the non-MDRO infection group (n = 238). Non-parametric tests, chi-square tests, and multivariate logistic regression analysis were used to identify the primary risk factors for MDRO infections. With the aid of analysis utilizing R software 4.4.1 (R Foundation for Statistical Computing, Vienna, Austria), we developed a nomogram prediction model, which was evaluated using the receiver operating characteristics (ROC) curve, calibration curve, and decision curve analysis (DCA). Results Age, antibiotic application time, and central venous catheterization were independent risk factors for MDRO infection (p < 0.05). The constructed nomogram prediction model for patients with MDRO infection has a C-index of 0.8640. The ROC curve results showed that the prediction model has a specificity of 0.7700, a sensitivity of 0.8800, and an area under the curve (AUC) of 0.8800. Conclusion This study identifies significant risk factors for MDRO infections in a cancer specialty hospital setting and offers a clinically useful prediction model, which may aid in targeted preventive measures and optimization of antibiotics usage, thereby potentially reducing the incidence and impact of these infections.

Epidemiology of Bacteremia in Patients with Hematological Malignancies and Hematopoietic Stem Cell Transplantation and the Impact of Antibiotic Resistance on Mortality: Data from a Multicenter Study in Argentina

The epidemiology of bacteremia and the antibiotic resistance profile (ARP) of Gram-negative bacilli (GNB) in hematological malignancies (HM) and hematopoietic stem cell transplant (HSCT) patients may differ according to geographic region. In addition, multidrug-resistant organisms (MDROs) may impact mortality. This is a prospective, observational, and multicenter study. The first episodes of bacteremia in adult patients with HM or HSCT were included. The risk factors for 30-day mortality were identified. One thousand two hundred and seventy-seven episodes were included (HM: 920; HSCT: 357). GNB were isolated in 60.3% of episodes, with Enterobacterales (46.9%) and P. aeruginosa (8.5%) being the most frequent. Gram-positive cocci were isolated in 41.9% of episodes, with coagulase-negative staphylococci (19.8%) and S. aureus (10.4%) being the most frequent. MDROs were isolated in 40.2% (24.4% GNB). The ARP of GNB in patients with HM vs. HSCT was cefepime: 36.8% vs. 45.7% (p = 0.026); piperacillin–tazobactam: 31.05% vs. 45.2% (p &lt; 0.0001); carbapenems: 18.9% vs. 27.3% (p = 0.012); and aminoglycosides: 9.3% vs. 15.4% (p = 0.017), respectively. Overall mortality between patients with HM and HSCT was 17.5% vs. 17.6% (p = 0.951), respectively. The risk factors for mortality were relapsed and refractory underlying disease, corticosteroids use, respiratory source, septic shock, and GNB resistant to meropenem, while 7-day clinical response was a protective factor for survival. Bacteremia was frequently caused by GNB, with a large proportion of MDROs and a high level of antibiotic resistance, especially in patients with HSCT. Carbapenem-resistant GNB bacteremia was associated with a significant increase in mortality.

Antimicrobial resistance in Enterobacterales, Acinetobacter spp. and Pseudomonas aeruginosa isolates from bloodstream infections in Australian children, 2013-2021.

Gram-negative bloodstream infections are associated with significant morbidity and mortality in children. Increasing antimicrobial resistance (AMR) is reported globally, yet efforts to track pediatric AMR at a national level over time are lacking. The Australian Group on Antimicrobial Resistance (AGAR) surveillance program captures clinical and microbiological data of isolates detected in blood cultures across Australia. EUCAST 2022 was used for MIC interpretation and the AMR package in R for data analysis. Over a nine-year period, there were 3,145 bloodstream infections with 3,266 gram-negative isolates reported in hospitalized children aged <18 years; 21.0% were from neonates. The median length of stay was 9 days, and 30-day all-cause mortality was 5.2%. A greater odds of death was observed in those with a multi-drug resistant organism (aOR: 2.1, 95%CI: 1.3, 3.3, p: 0.001). Escherichia coli (44.5%) and Klebsiella pneumoniae complex (12.6%) were the two most frequently reported organisms. Overall resistance in Enterobacterales to gentamicin/tobramycin was 11.6%, to ceftazidime/ceftriaxone was 12.9%, and 13.2% to ciprofloxacin. Resistance increased over time.Of 201 Pseudomonas aeruginosa isolates reported, 19.7% were resistant to piperacillin-tazobactam, 13.1% resistant to cefepime/ceftazidime and 9.8% to ciprofloxacin. Of 108 Acinetobacter spp. isolates, one was resistant to meropenem, and two were resistant to ciprofloxacin. Resistance did not increase over time. AMR in gram-negative organisms causing bloodstream infections in Australian children is increasing which should be considered when updating guidelines and empiric treatment regimens. Ongoing pediatric-specific national surveillance with pediatric reporting must remain a priority to strengthen antimicrobial stewardship and infection control programs.

Therapy of Aspiration: Out-of-Hospital and In-Hospital-Acquired.

Therapeutic considerations for aspiration pneumonia prioritize the risk of multidrug-resistant organisms. This involves integrating microbiological insights with each patient's unique risk profile, including the location at the time of aspiration, and whether it occurred in or out of the hospital. Our understanding of the microbiology of aspiration pneumonia has also evolved, leading to a reassessment of anaerobic bacteria as the primary pathogens. Emerging research shows a predominance of aerobic pathogens, in both community and hospital-acquired cases. This shift challenges the routine use of broad-spectrum antibiotics targeting anaerobes, which can contribute to antibiotic resistance and complications such as Clostridium difficile infections-concerns that are especially relevant given the growing issue of antimicrobial resistance. Adopting a comprehensive, patient-specific approach that incorporates these insights can optimize antibiotic selection, improve treatment outcomes, and reduce the risk of resistance and adverse effects.

A Retrospective Closed Cohort Study on Distribution of Multidrug-Resistant Bacteria in Ventilator-Associated Pneumonia and its Impact on Patient Outcome.

Ventilator-associated pneumonia (VAP) is a common and serious nosocomial infection affecting critically ill patients undergoing mechanical ventilation. This study investigated the prevalence of multidrug-resistant (MDR) organisms in VAP, the VAP rate, and the outcomes associated with MDR-VAP. This retrospective single-center study, conducted in 2022, included adult ICU cases from April 2021 to March 2022, receiving mechanical ventilation for more than 48 h. Patient data were analyzed for demographics, comorbidities, empirical antibiotic use, and outcomes. MDR organisms were identified in respiratory cultures. Among 447 patients, 133 developed VAP, with 96 cases being MDR-VAP. The mean age of the overall VAP population was 52 years, 70% of which were males. The incidence of VAP was 30.0% (95% CI: 25.7%-34.5%), while that of MDR-VAP was 21.6% (95% CI: 17.9%-25.8%). The most prevalent MDR organisms were Acinetobacter species (50%) and Klebsiella pneumoniae (46.9%). Empirical antibiotics were administered in 96% of VAP cases. The overall VAP rate was 38.03/1000 ventilator days. No single antimicrobial agent seemed to offer an empirical cover, as the susceptibility rate for most tested antimicrobials was less than 85%. Patients with MDR-VAP had a low survival rate (64.6%) and were less likely to be extubated at 13.5% compared to non-MDR-VAP (survival rate of 62.2%). COVID-19 patients had a high incidence of MDR VAP, especially with Acinetobacter. Overall, VAP mortality was 57.1%. The median ventilator days were 16 for VAP and only four for non-VAP. Gram-negative organisms, particularly Klebsiella and Acinetobacter, were the main MDR VAP culprits. MDR-VAP exhibited higher morbidity and mortality. A study focused on developing resistance by microorganisms is warranted for further understanding.