Carbapenem-resistant Enterobacteriaceae Infections Research Articles

Discovery of Broad‐Spectrum Repurposed Drug Combinations Against Carbapenem‐Resistant Enterobacteriaceae (CRE) Through Artificial Intelligence (AI)‐Driven Platform

AbstractAntimicrobial resistance challenges the sustainability of healthcare systems and results in substantial economic losses worldwide. This issue is further aggravated by paucity of new drugs and treatment options. In this study, an artificial intelligence (AI)‐derived platform termed IDentif.AI is utilized to accelerate the development of effective therapeutic options for carbapenem‐resistant Enterobacteriaceae (CRE). Twelve Food and Drug Administration‐approved drugs are selected and the in vitro inhibitory efficacy of 155 combinations consisting of various drugs is determined at different concentrations against both Klebsiella pneumoniae and Escherichia coli. Correlating these experimental data via an AI‐derived relationship, IDentif.AI rapidly determines a ranked list of drug combinations in the search space of over half a million possible combinations. Meropenem is found to strongly synergize with low doses of the anticancer drug bleomycin, showing broad‐spectrum, bactericidal activity against nine isolates across three CRE species in rich and minimal media with no synergistic cytotoxicity on mammalian cells. Synergy is also detected between bleomycin and other key carbapenems in clinical use (imipenem, ertapenem). Bleomycin/carbapenem appears to be a promising combination therapy for treating various CRE infections. IDentif.AI shows profound capability of identifying pan‐active drug combinations against a family of bacteria through surveying strains from different species in parallel.

Retrospective Tertiary Care-Based Cohort Study on Clinical Characteristics and Outcomes of Ceftazidime-Avibactam-Resistant Carbapenem-Resistant Klebsiella pneumoniae Infections.

The advent of ceftazidime-avibactam (CAZ-AVI)-resistant carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates has been steadily documented in recent years. We aimed to identify risk factors of CAZ-AVI-resistant CRKP infection and assess clinical outcomes of patients. The study retrospectively examined the clinical and microbiological data of patients with ceftazidime avibactam susceptible and ceftazidime avibactam-resistant Klebsiella pneumonia carbapenem-resistant enterobacteriaceae infection to identify risk factors, clinical features, and outcomes using multivariate logistic regression analysis. A total of 152 patients with CRKP infection were enrolled in this study. Patients with CAZ-AVI-resistant CRKP isolates (20/34 = 58.8%) had prior exposure to carbapenems (p=0.003) and had more tracheostomies (16/34 = 47.1%) (p=0.001). Only 8/28 (28.6%) patients with CAZ-AVI susceptible CRKP isolates died amongst those administered ceftazidime-avibactam compared to 49/90 (54.4%) who did not receive the same (p=0.016). 1/9 (11.1%) patients with CAZ-AVI-resistant CRKP isolates who received colistin died compared to 13/25 (52%) who did not receive colistin (p=0.03). There was no association between presence of CAZ-AVI-resistant CRKP isolates and overall mortality (odds ratio: 0.7; 95% CI: 0.3, 1.6), and no independent predictors of risk factors to overall mortality in the group with CAZ-AVI-resistant CRKP isolates were noted. Early advent of CAZ-AVI resistance in CRE isolates highlights the dynamic necessity of routine CAZ-AVI resistance laboratory testing and antimicrobial stewardship programmes focusing on the utilization of all antibiotics. Consolidating the hospital infection control of tracheostomies may help to prevent CAZ resistance in CRKP. Colistin may aid in decreasing of mortality rates among patients with CAZ-AVI CRKP isolates.

Insights and Opinions of Critical Care Healthcare Professionals in the Management of Carbapenem-resistant Enterobacteriaceae Cases and Antibiotic-Resistant Infections in the Intensive Care Unit Setting: A Survey-Based Approach.

A survey-based approach to managing antibiotic-resistant infections in the intensive care unit (ICU) setting, with a focus on carbapenem-resistant Enterobacteriaceae (CRE) cases, was conducted. Among CRE, New Delhi metallo-β-lactamase 1 (NDM-1) is a carbapenemase that is resistant to β-lactam antibiotics and has a broader spectrum of antimicrobial resistance than other carbapenemase types. The article explains that healthcare-associated infections (HAIs) are a significant problem, particularly in low- and middle-income countries, and that carbapenem in combination with other antibiotics are the most potent class of antimicrobial agents effective in treating life-threatening bacterial infections, including those caused by resistant strains. The survey aimed to gather critical care healthcare professionals (HCPs') opinions on their current practices in managing infections acquired in the hospital and ICU settings, with a focus on CRE cases, specifically NDM-1 and other antibiotic-resistant infections. Responses from critical care healthcare professionals, including online surveys and in-person interviews, to gain insights into the management of infections caused by multidrug-resistant bacteria. The findings related to the insights on the prevalence of bacterial flora, clinical experiences on efficacy and safety of meropenem sulbactam ethylenediaminetetraacetic acid (EDTA) (MSE) in CRE cases, and various combination therapies of antibiotics used to treat antibiotic-resistant infections in ICU setting were evaluated. Klebsiella pneumoniae bacteria were the most common bacteria in cultures, followed by Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. NDM-1 was the type of carbapenemase found in around 50% of CRE patients. MSE is among the most preferred antibiotics besides colistin, polymyxin B, and ceftazidime avibactum for CRE cases and specifically for NDM-1 cases due to its high rate of efficacy and safety. The article concludes with a discussion on the antibiotics used in response to CRE cases, reporting that critical care HCP considers MSE with high efficacy and safe antibiotic combination and was used as both monotherapy and in combination with other antibiotics. The survey highlights the need for exploring and better understanding the role of MSE in the management of CRE infections, especially in NDM-1.

Role of Probiotics in Preventing Carbapenem-Resistant Enterobacteriaceae Colonization in the Intensive Care Unit: Risk Factors and Microbiome Analysis Study.

Older patients with multiple comorbidities often necessitate prolonged hospital stays and antibiotic treatment in the intensive care unit (ICU), leading to a rise in multidrug-resistant organisms like carbapenem-resistant Enterobacteriaceae (CRE). This study examined risk factors for carbapenem-resistant Enterobacteriaceae colonization in the ICU and assessed probiotics' preventive role. In this single-center, retrospective study, 9099 ICU patients were tested for stool CRE culture from March 2017 to April 2022. We excluded 136 patients with CRE colonization within one week post-admission and 26 who received probiotics before CRE colonization. Ultimately, 8937 CRE-negative patients were selected. Logistic analysis identified CRE colonization risk factors and evaluated probiotics' influence, including Saccharomyces boulardii or Lactobacillus rhamnosus, used by 474 patients (5.3%) in the ICU. Compared with data on initial admission, 157 patients (1.7%) had newly discovered CRE colonization before discharge. In a multivariate analysis, coronavirus disease 2019, the ICU, tube feeding, antibiotics such as aminoglycoside, extended-spectrum penicillin, stool vancomycin-resistance enterococci colonization, and chronic kidney disease were significantly associated with de novo CRE infection. However, probiotic use was negatively correlated with CRE infection. Managing risk factors and administering probiotics in the ICU may help prevent CRE colonization; large randomized prospective studies are needed.

Management of Carbapenem-Resistant Enterobacteriaceae Bloodstream Infections: An Experience from a Tertiary Care Centre in Oman

The emergence of Carbapenem-resistant Enterobacteriaceae (CRE)is a public health concern worldwide. It is associated with increased mortality due to limited antibiotics available to treat CRE infections. The aim of this study was to understand the epidemiology of CRE infections, associated mortality, and available treatment options. All patients with CRE isolated in blood culture were identified between December 2011 and October 2019. Risk factors and mortality associated with each risk factor at 14 and 30 days were determined.55 cases of CRE bloodstream infections were isolated, with a median age of 56 years. Eighty-four percent of patients received treatment in the ICU. All cases were caused by Klebsiella pneumonia. The rate of resistance to the tested antibiotics was as follows: meropenem 92% (50/54), imipenem 75% (40/53), etrapenam 95% (19/20), Amikacin 71% (37/52), cotrimoxazole 73% (40/53), Gentamicin 47% (25/53) and colistin 7% (3/41). Major risk factors associated were the presence of a urinary catheter (84%), central venous catheter (78%), mechanical ventilation (74%) and post-surgery (67%). Mortality at 14 days and 30 days was 41%, and 52%, respectively. Univariate analysis showed that 14 days mortality was higher in patients with central venous catheter (P=0.01). Charlson's comorbidity index was associated with an increased risk of death at 30 days (P=0.04). There was no statistically increased survival in those treated with combination therapy at 30 days (P=0.5). The mortality of CRE infections seems to be high and optimal therapy is not yet well defined. Combination therapy is not associated with increased survival in this cohort of patients.

Detection of Carbapenem Resistance among Enterobacteriaceae Pathogens Isolated from Clinical Samples in Shendi locality

Introduction: The majority of antimicrobial agents are ineffective against carbapenem-resistant Enterobacteriaceae (CRE) infections, leading to unfavorable clinical consequences. This fact is associated with higher mortality and morbidity rates, prolonged hospital stays, and increased treatment-related costs. Carbapenems are the last line for the treatment of infection caused by bacteria resistance to a broad spectrum of antibiotics. Objective: This study aimed to detect the Distribution of Carbepanems Resistance in Enterobacteriaceae Pathogens Isolated from Clinical Samples in the Shendi locality. Methods: A cross-sectional study and a laboratory-based study were carried out on 63 isolates from different specimens, 63 types of pathogenic bacteria were isolated and identified using Gram stain, biochemical reactions, and testing for their susceptibility to Carbapenems antibiotics was performed for all Enterobacteriaceae isolates. Result: The isolated Enterobacteriaceae comprising of 19.0(30.2%) E.coli, 17 (27.0%) K. pneumoniae, 13(20.6%) P. vulgaris, 5(7.9%) P. mirabilis, 1(1.6%) Enterobacter species, 3(4.8%) C. freundii and 5(7.9%) M. morganii. Carbapenem (Imipenem and meropenem) susceptibility testing showed that 36.0% of Enterobacteriaceae isolates were Carbapenem-resistant. Conclusions: The study revealed the low resistance pattern of Enterobacteriaceae to Carbapenems. Despite that E.coli (19.0, 30.0%) was the most isolated organism, and K. pneumonia (7.0, 11.0%) was the most resistant isolate to Carbapenems. The urine sample had the highest degree of resistance. There was a correlation between patients with chronic diseases such as cancer and the resistance level to Carbapenems, while there was no statistical significance between the period of antibiotics usage and the degree of resistance.

The Comparative Efficacy of Ceftazidime–Avibactam with or without Aztreonam vs Polymyxins for Carbapenem-resistant Enterobacteriaceae Infections: A Prospective Observational Cohort Study

The Comparative Efficacy of Ceftazidime–Avibactam with or without Aztreonam vs Polymyxins for Carbapenem-resistant Enterobacteriaceae Infections: A Prospective Observational Cohort Study

Mortality Risk and the Clinical Outcome of Carbapenem-Resistant Enterobacteriaceae Carriers with Neutropenia: A Matched Case-Control Study

Patients with hematologic diseases are often accompanied by immunodeficiency, treatments as well as the disease itself can lead to granulocyte deficiency. Patients with granulocyte deficiency are under the high risk of infection. In recent years, the rate of Carbapenem-resistant Enterobacteriaceae (CRE) infection has gradually increased. Treatment options of CRE infection is limited, and effective anti-infection treatment is usually delayed, leading to the death of patients due to infection. CRE screening can provide clinical evidence for early detection of CRE by clinicians, thereby formulating antimicrobial treatment strategies. However, whether the initial empirical treatment covering CRE can improve the adverse outcomes of patients still lacks a definitive conclusion. We collected clinical data on patients with neutropenia who also undergoing CRE screening between January 2017 and December 2022. To further analyze the impact of CRE positivity on patient mortality risk and the clinical effectiveness of initial empirical treatment for CRE, we conducted two case-cohort studies with clinical baseline data matching. In total, we performed 3529 fecal CRE screenings from 664 patients. Out of these, 345 screenings from 135 patients tested positive for CRE. We identified 16 different strains, with the most common being Klebsiella pneumoniae (184/345), followed by Escherichia coli (76/345). To determine the influence of CRE positivity on patient mortality rates, we conducted a 1:2 case matching based on age, gender, diagnosis, and medical history of CRE-positive patients (Table 1). The results showed that in the overall analysis, CRE positivity, age over 60, and male gender were adverse factors influencing mortality. However, in the subgroup analysis of CRE-positive patients, no adverse factors affecting mortality were observed. To further assess the impact of CRE positivity on patient infection outcomes, we defined the initial antibiotic treatment strategies for a total of 4,872 infection events in screened patients. We divided them into the following groups: the empirical treatment group without CRE results (n=3,954), the empirical treatment group not covering CRE (n=122), and the CRE based empirical treatment group (n=796). The CRE based empirical treatment group had a higher success rate in initial empirical treatment compared to the group without covering CRE (65.5% vs. 59.0%). To further investigate the differences in initial empirical treatment success rates and 30-day mortality rates between patients in the CRE-based empirical treatment group and empirical treatment group without CRE covering, we performed 1:2 case matching for clinical baseline data on age, sex, diagnosis, past history, and disease status at infection according to the clinical characteristics of the CRE-based anti-infection treatment group. The results indicated that there were no significant differences in initial empirical treatment success rate and 30-day mortality rate between the CRE-based empirical treatment group and case-matched controls. In conclusion, diagnosing and treating patients with CRE infection presents significant challenges. Early screening for CRE and empirical treatment targeting CRE can increase the success rate of initial empirical treatment in CRE-positive patients.

Mortality rate and factors associated with mortality of carbapenem-resistant Enterobacteriaceae infection.

Background: Carbapenem-resistant Enterobacteriaceae (CRE) is a serious pathogen with high mortality. Recognition of factors associated with mortality and treating these modifiable factors are crucial to reducing mortality.Objective: To determine the 30-day mortality and factors associated with a 30-day mortality of CRE infection.Methods: A retrospective cohort study was conducted between January 1, 2015, and December 31, 2019. All patients diagnosed with CRE infection aged ≥18 years were included. Multivariate logistic regression was used for evaluating the factors associated with 30-day mortality and presented as adjusted odds ratio (aOR) with 95% confidence interval (CI).Result: One hundred and ninety-four patients were enrolled. The 30-day mortality occurred in 75 patients (38.7%). The common antibiotic regimen was monotherapy and combination of carbapenem, colistin, amikacin, tigecycline, and fosfomycin. CRE isolates were susceptible to tigecycline (93.8%), colistin (91.8%), fosfomycin (89.2%), and amikacin (89.2%). The independent factors associated with 30-day mortality were an increasing simplified acute physiology (SAP) II score (aOR 1.11, 95% CI 1.05-1.16, p < 0.001), sepsis at time of CRE infection diagnosis (aOR 7.93, 95% CI 2.21-28.51, p = 0.002), pneumonia (aOR 4.48, 95% CI 1.61-12.44, p = 0.004), monotherapy (aOR 4.69, 95% CI 1.71-12.85, p = 0.003), and improper empiric antibiotic (aOR 5.13, 95% CI 1.83-14.40, p = 0.002).Conclusion: The overall 30-day mortality of CRE infection was high. The factors associated with mortality were an increasing SAP II score, sepsis at time of CRE infection diagnosis, pneumonia, monotherapy, and improper empiric antibiotic. The study suggested that proper empiric antibiotic and combination antibiotics might reduce mortality from CRE infection.

Carbapenem-Resistant Enterobacteriaceae Bacteraemia in Intensive Care Unit: A Descriptive Study on Risk Factors and Clinical Outcome

INTRODUCTION: Over the past 10 years, the prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing dramatically with numerous hospital outbreaks reported. Bacteraemia caused by CRE have limited treatment options and have been associated with high mortality rates. As a result, preventing both CRE transmission and CRE bloodstream infections have become important objectives in managing intensive care unit (ICU) patients. The study aims to determine the incidence and risk factors of CRE bacteraemia in intensive care settings, and its’ clinical outcome. MATERIALS AND METHODS: A retrospective, descriptive study was conducted, where data of the patients admitted to general ICU of Hospital Pulau Pinang from January 2017 till December 2018 were collected and assessed for incidence, presence of predisposing factors and clinical outcome for CRE bloodstream infection. RESULTS: Out of 2,585 total ICU admissions, there were 37 cases of CRE bacteraemia with an incidence rate of 1.43%. An analysis of risk factors revealed that the use of indwelling catheter has the highest association with CRE bacteraemia in which 95% of the patients were exposed. The commonest organisms of CRE bacteraemia were Klebsiella pneumoniae (97.3%) and Escherichia coli (2.7%). The 30-day mortality rate after CRE bacteraemia was 78.4%. CONCLUSION: CRE bacteraemia among ICU patients showed a high mortality rate. Most of the patients were exposed to multiple risk factors. A high index of suspicion and rapid identification of patients at risk for CRE infection are important for effective therapy and initiation of infection control measures to prevent further spread.

B-066 Evaluation on Effectiveness of Colloidal Gold Immunochromatography Assay for Rapid Detection of Carbapenemase-producing Enterobacteriaceae

Abstract Background The identification, treatment, and control of carbapenem-resistant Enterobacteriaceae (CRE) infections are a major challenge for health care institutions and diagnostic laboratories worldwide. A novel Carbapenemase-producing Bacteria Test Kit (Lateral Flow Assay) from Dynamiker Biotechnology (Tianjin) Co., Ltd. is a qualitative test that was easy to operate and can be widely accepted by clinical and primary medical. Results can be read in just 15 minutes using colloidal gold immunochromatography, which can detect double and multiple carbapenemase types (Fig. 1). We analyzed the effectiveness of Dynamiker carbapenemase-producing bacteria test kit for rapid detection of CRE carbapenemase. Methods A total of 120 strains of Enterobacterales in blood culture were collected, including 80 strains of CRE and 40 strains of CSE (carbapenem-susceptibility Enterobacteriaceae). PCR was used to detect KPC, NDM, IMP, VIM and OXA-48 genes as gold standard. Dynamiker carbapenemase-producing bacteria test kit was used to detect the carbapenemase produced by CRE, which was conducted by the performance evaluation combined with PCR results. Results The 80 strains of CRE expressing carbapenemase genes were all positive for the detection of carbapenemasstre by Dynamiker carbapenemase-producing bacteria test kit, which includes 39 strains producing KPC, 26 strains producing NDM, 8 strains producing IMP, 5 strains producing VIM and 2 strains producing OXA-48 enzymes; the 40 strains of CSE were negative and no carbapenemase were detected. Compared with the PCR results, the sensitivity and specificity of the four enzymes by Dynamiker carbapenemase-producing bacteria test kit were both 100% (Fig. 2). Conclusion Dynamiker carbapenemase-producing bacteria test kit can be applied as a simple, rapid, sensitive and specific diagnostic method for the detection of different CRE carbapenemase types, which is of great value for the accurate use of clinical anti-infective therapy.Fig. 1.Operating procedures of colloidal gold immunochromatography.Fig. 2.Results of Dynamiker carbapenemase-producing bacteria test kit C: Control, K: KPC, N: NMD, I: IMP, V: VIM, O: OXA-48.

Asymptomatic gastrointestinal carriage of multidrug-resistant carbapenemase-producing Enterobacteriaceae among children under five years in a Kenyan hospital

ObjectivesAsymptomatic gastrointestinal carriage of carbapenem-resistant Enterobacteriaceae (CRE) is a threat to global health in developing countries with inadequate safe drinking water, poor hygiene, and weak antimicrobial stewardship; however, epidemiological data to guide CRE infection prevention and control is limited in these settings. We assessed asymptomatic CRE and carbapenem-producing Enterobacteriaceae (CPE) fecal carriage rates and associated risk factors among hospitalized children aged under 5 years. MethodsWe adopted a cross-sectional study at Mama Lucy Kibaki Hospital in Nairobi-City County, Kenya, between June and September 2022. We collected demographic and clinical characteristics using a structured questionnaire and clinical reports and analyzed stool/rectal swab samples by standard and automated bacteriological methods. ResultsAsymptomatic CRE and CPE fecal carriage rate was 2.25% (6/267), with six isolates recovered, predominated by Escherichia coli (33.33%) and Enterobacter cloacae subsp dissolvens (33.33%). Third-generation cephalosporin and ciprofloxacin resistance were highest in Citrobacter farmer and E. cloacae subsp cloacae. All CRE and CPE were multidrug-resistant, and except E. cloacae subsp cloacae, were 100% colistin-resistant. ConclusionsAsymptomatic gastrointestinal carriage of multidrug-resistant-CRE among hospitalized children under 5 years, presents a substantial public health threat. This calls for continuous surveillance including molecular characterization of isolates, to inform infection prevention and antimicrobial stewardship adherence in line with local and global plans on AMR.

Effect of antibiotic de-escalation on clinical outcomes in patients with carbapenem-resistant Enterobacteriaceae bacteremia (CRE) in the hematology-oncology setting.

Carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with poor outcomes, particularly among hematology-oncology patients. Appropriate use (selection and de-escalation) of antibiotics is a key component of management of febrile neutropenia particularly in high CRE prevalence regions like India. This was a retrospective study done (April 2019-December 2021) in a dedicated oncology center in North India, which assessed the case records of the patients undergoing therapy for hematological malignancies who were diagnosed with CRE bacteremia. Demographic, clinical and microbiological data, as well as antibiotic prescription patterns were studied. Inter-group analysis was done between an antibiotic stewardship cohort (avoiding CRE therapy empirically or stopping CRE therapy if cultures negative; as per suggestions of the AMS team) and a non-antibiotic stewardship cohort (continuation of empirical CRE therapy; de-escalation advice was not followed). A total of 139 patients were identified, with median age of 41 years (range 13-74) out of which 82 (58.9%) were males. Acute myeloid leukemia (66.2%) was the most common malignancy, followed by lymphoma (8.6%) and myeloma (8.6%). Nearly 30% of patients were post allogenic stem cell transplant. Klebsiella pneumoniae was the predominant organism (78.4%) and combination of NDM+OXA-48 (46.3%) was the most common carbapenemase gene detected followed by OXA-48 alone (34.7%). Overall, 28-day mortality was 26.6%. On binary logistic regression analysis, lack of compliance with antibiotic stewardship intervention was an independent predictor of mortality (p=0.005). Prior exposure to empirical CRE therapy or failure to de-escalate was associated with poor outcomes in patients with CRE bacteremia, which gives us a window of antibiotic stewardship in febrile neutropenia.

Emergence of Tigecycline and Carbapenem-Resistant Citrobacter freundii Co-Carrying tmexCD1-toprJ1, blaKPC-2, and blaNDM-1 from a Sepsis Patient.

This research aims to profile ten novel strains of carbapenem-resistant Enterobacteriaceae (CRE) co-carrying blaKPC and blaNDM. Clinical CRE strains, along with corresponding medical records, were gathered. To ascertain the susceptibility of the strains to antibiotics, antimicrobial susceptibility tests were conducted. To validate the transferability and cost of fitness of plasmids, conjugation experiments and growth curves were employed. For determining the similarity between different strains, ERIC-PCR was utilised. Meanwhile, whole genome sequencing (WGS) was performed to characterise the features of plasmids and their evolutionary characteristics. During the course of this research, ten clinical CRE strains co-carrying blaKPC and blaNDM were gathered. It was discovered that five out of these ten strains exhibited resistance to tigecycline. A closer examination of the mechanisms underlying tigecycline resistance revealed that tmexCD1-toprJ1, blaKPC-2, and blaNDM-1 existed concurrently within a single Citrobacter freundii strain (CF10). This strain, with a minimum inhibitory concentration (MIC) of 32 mg/L to tigecycline, was obtained from a sepsis patient. Furthermore, an investigation of genome evolution implied that CF10 belonged to a novel ST type 696, which lacked analogous strains. Aligning plasmids exposed that similar plasmids all had less than 70% coverage when compared to pCF10-tmexCD1, pCF10-KPC, and pCF10-NDM. It was also found that tmexCD1-toprJ1, blaKPC-2, and blaNDM-1 were transferred by Tn5393, IS5, and Tn6296, respectively. This research presents the first report of coexistence of tmexCD1-toprJ1, blaKPC-2, and blaNDM-1 in a carbapenem and tigecycline-resistant C. freundii strain, CF10. Tigecycline is considered a "last resort" antibiotic for treating CRE infections. The ongoing evolution of resistance mechanisms to both carbapenem and tigecycline presents an alarming situation. Moreover, the repeated reporting of both these resistance mechanisms within a single strain poses a significant risk to public health. The research revealed that the genes tmexCD1-toprJ1, blaKPC-2, and blaNDM-1, which cause carbapenem and tigecycline-resistance in the same strain, were located on mobile elements, suggesting a potential for horizontal transmission to other Gram-negative bacteria. The emergence of such a multi-resistant strain within hospitals should raise significant concern due to the scarcity of effective antimicrobial treatments for these "superbugs".

Secondary bacterial infections & extensively drug-resistant bacteria among COVID-19 hospitalized patients at the University Hospital in Kraków

IntroductionHealthcare-associated infections (HAI) and bacterial antimicrobial resistance posed a therapeutic risk during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to analyze the HAIs in COVID-19 patients in the Intensive Care Unit (ICU) and non-ICU at the University Hospital in Krakow (UHK) with an emphasis on the susceptibility of the most frequently isolated pathogens and the prevalence of extensively drug resistant (XDR) microorganisms.MethodsThis laboratory-based study was carried out at the University Hospital in Krakow in the ICU and non-ICUs dedicated to COVID-19 patients between May 2021 and January 2022. All isolates of Klebsiella pneumoniae were analyzed using PFGE protocol.Results292 independent HAI cases were identified, with the predominance of urinary tract infections (UTI), especially in the non-ICU setting. The most common ICU syndrome was pneumonia (PNA). The prevalence of XDR organisms was 22.6% in the ICU and 14.8% in non-ICUs among all isolates. The incidence of carbapenem-resistant Enterobacteriaceae infection was 24.8 cases per 10,000 hospitalizations and the carbapenem-resistant A. baumannii infection incidence was 208.8 cases per 10,000 hospitalizations. The prevalence of XDR strains was highest in Acinetobacter spp, in PNA cases. The PFGE typing demonstrated that almost all XDR strains varied widely from each other.ConclusionsIn this study, there was a high incidence of HAI in COVID-19 patients, especially when compared to Western Europe and the United States. Similarly, the prevalence of XDR microorganisms, especially XDR-A.baumannii, was also high. PFGE did not confirm the horizontal spread of any organism strains.

Endogenous Bacteremia Caused by Intestinal Colonization of Carbapenem-Resistant Enterobacteriaceae (CRE) in Immunocompromised Children.

Carbapenem-resistant Enterobacteriaceae (CRE) infection is life-threatening, especially for immunocompromised children. The source tracking of CRE could prevent bacteremia during hospitalization. In this study, the intestinal colonization of CRE and their translocation to blood were investigated. Stool samples from immunocompromised pediatric patients were collected after admission, and secondary stool and blood samples were collected in case of fever. After CRE phonotypic detection, the OXA-48, NDM-1, VIM, IMP, and KPC genes were detected by PCR. Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) was used to determine the phylogenic relatedness of the blood and fecal isolates. Bacteremia was recorded in 71.4% of the patients. Enterobacteriaceae spp. were recorded in 100% of the stool samples and 31% of the blood samples. The correlation between the length of stay (LOS), days of fever, chemotherapy regimens, and death rate was significant (p-value ≤ 0.05). OXA-48 was present in all CRE isolates in both the primary and the secondary stool samples and the blood samples. According to the phylogenetic data, 58.33% of the patients with bacteremia had identical blood and stool isolates. The death rate was 24.4% in children with CRE bacteremia. The primary intestinal colonization with CRE in immunocompromised pediatrics and their translocation to blood was established in this study. The implementation of infection control programs and the application of infection prevention strategies for immunocompromised children is necessary.

Simultaneous and Visual Detection of KPC and NDM Carbapenemase-Encoding Genes Using Asymmetric PCR and Multiplex Lateral Flow Strip.

Carbapenem-resistant Enterobacteriaceae (CRE) infections constitute a threat to public health, and KPC and NDM are the major carbapenemases of concern. Rapid diagnostic tests are highly desirable in point-of-care (POC) and emergency laboratories with limited resources. Here, we developed a multiplex lateral flow assay based on asymmetric PCR and barcode capture probes for the simultaneous detection of KPC-2 and NDM-1. Biotinylated barcode capture probes corresponding to the KPC-2 and NDM-1 genes were designed and cast onto two different sensing zones of a nitrocellulose membrane after reacting with streptavidin to prepare a multiplex lateral flow strip. Streptavidin-coated gold nanoparticles (SA-AuNPs) were used as signal reporters. In response to the target carbapenemase genes, biotin-labelled ssDNA libraries were produced by asymmetric PCR, which bond to SA-AuNPs via biotin and hybridise with the barcode capture probe via a complementary sequence, thereby bridging SA-AuNPs and the barcode capture probe to form visible red lines on the detection zones. The signal intensities were proportional to the number of resistance genes tested. The strip sensor showed detection limits of 0.03 pM for the KPC-2 and 0.07 pM for NDM-1 genes, respectively, and could accurately distinguish between KPC-2 and NDM-1 genes in CRE strains. For the genotyping of clinical isolates, our strip exhibited excellent consistency with real-time fluorescent quantitative PCR and gene sequencing. Given its simplicity, cost-effectiveness, and rapid analysis accomplished by the naked eye, the multiplex strip is promising auxiliary diagnostic tool for KPC-2 and NDM-1 producers in routine clinical laboratories.

#3722 CARBAPENEM-RESISTANT ENTEROBACTERIACEAE URINARY TRACT INFECTION IN RENAL TRANSPLANT RECIPIENTS: ROLE OF A NOVEL ANTIBIOTIC REGIMEN

Abstract Background and Aims Urinary tract infection (UTI), the most common bacterial infection among renal transplant recipients (RTRs), remains a challenge, particularly given the increased incidence of MDR organisms, including Carbapenem-resistant Enterobacteriaceae (CRE). CRE infections were associated with inferior patient and graft outcomes compared to other bacterial infections. Paradoxically, there have been no guidelines on managing CRE in RTRs besides multiple challenges, including the bacteriostatic nature, poor urinary concentration, and dose-limiting adverse effects of various antibiotics. The current study designed and assessed the outcomes of protocol-based therapy consisting of high-dose Meropenem in combination with other antibiotics followed by prolonged oral administration. Method This is a single-centre retrospective study conducted in the department of Nephrology and Renal transplantation, Sanjay Gandhi Post Graduate Institute of Medical Sciences, India, between 1st August 2016 till 31st July 2022. All the RTRs aged $ \ge $ 18 years admitted between 1st August 2016 and 31st July 2018 with symptomatic UTI and a urine culture positive for CRE were included in the study. Patients who received various antibiotics conventionally based on the treating physician's decision from August 2016 to July 2017 were considered under the Best available treatment (BAT) group, while the Standardized Therapeutic Antibiotic Regimen (STAR) group included patients treated from August 2017 to July 2018. The treatment of the STAR group consists of a therapeutic phase for at least six weeks (IV therapeutic phase for two weeks total or one week after the clinical recovery, whichever is later + Oral Therapeutic phase for four weeks) followed by an oral chemoprophylaxis phase for three months. Following the treatment of index UTI episodes due to CRE, follow-up both groups’ follow-up data until a minimum of four years were collected. Appropriate statistical tools were applied, and analyses were performed by SPSS software, version 25. Results A total of 37 patients fulfilling the inclusion criteria were included in the study, of which 13 patients were under the BAT group, and 24 were treated by the STAR-based protocol. The mean age of the study population was 37.6 $ \pm \ $12.3 years, and all were males. Most patients (70.2%) had the UTI due to CRE within one-month post-transplant, and the median duration of UTI post-transplant was 6.1 days (IQR: 4.5 – 33). The primary outcome, recurrence rates of UTI at 48-month follow-up among the patients in the STAR group, was significantly lower than those in the BAT group (30.4% vs 77.8%, p = 0.01). The death-censored graft survival was also significantly better among the STAR group than the BAT group (100% vs 75%, p = 0.03) after 48 months. Graft function at 48 months was also better in the STAR group (Serum creatinine- 1.4 ± 0.8 mg/dl vs 2.9 ± 2.2 mg/dl, p = 0.007). The patient survival, however, was similar among the two groups (95.8% vs 88.9%, p = 0.47). Conclusion Prolonged and combination antibiotic therapy followed by long-term antibiotic prophylaxis significantly reduced the recurrence of UTI due to CRE among the RTRs. Graft function and death-censored graft survival were also considerably better. Hence, the current study may pave the path for future RCTs based on combination antibiotic therapy as a solution to combat the challenge of CRE in RTRs.

Carbapenem-Resistant Enterobacteriaceae Infection in Immunocompromised Children with CRE Colonization: Incidence and Outcomes in an Antibiotic-Limited Setting

Objective: To determine the incidence of carbapenem-resistant Enterobacteriaceae (CRE) infection in patients with CRE colonization and compare the treatment outcomes between febrile patients with non-septic presentation who received empirical treatment with meropenem and those who did not. Material and Methods: The medical records of febrile patients with CRE colonization aged <15 years who were hospitalized at Songklanagarind Hospital between January 2018 and December 2020 were reviewed. Results: Among the 61 patients with CRE colonization, CRE infection was identified during eight febrile episodes in six patients (9.8%). Hematologic malignancies, solid tumors, and other diseases were diagnosed in 21 (34.4%), 25 (41.0%), and 15 (24.6%) patients, respectively. The median (interquartile range [IQR]) duration from CRE colonization to the first episode of fever was 22 (1.8–60.8) days. Among the 82 febrile episodes without initial sepsis or central nervous system infection, 19 and 63 episodes, respectively, were initially treated with meropenem and non-carbapenems. Treatment outcomes—including the proportion of patients needing step-up antibiotics (21.1% vs. 36.5%), development of sepsis (5.3% vs. 15.9%), and death within 30 days (6.6% vs. 9.8%) - were not significantly different between the two groups.Patients who developed sepsis had significantly higher resistance to empirical antibiotics (75% vs. 26.3%) as well as a significantly higher incidence of severe neutropenia lasting more than one week (85.7% vs. 21.9%) than those without sepsis.Conclusion: Patients with CRE colonization who exhibit fever without clinical sepsis and have an absolute neutrophil count >100 cells/mm3 can be empirically treated with non-carbapenems.

First Detection of blaNDM-1-Haboring IncHI2 Plasmid in Escherichia coli Strain Isolated from Goose in China.

Carbapenem-resistant Enterobacteriaceae infections are among the most serious threats to human and animal health worldwide. Of the 1013 strains of Escherichia coli isolated and identified in 14 regions of China from 2007 to 2018, seven strains were resistant to meropenem and all were positive for blaNDM. The seven New Delhi metallo-β-lactamase (NDM)-positive strains belonged to five different sequence types, indicating that most of the NDM-positive strains were nonclonal. An IncHI2 plasmid carrying the blaNDM-1 element was identified in the C1147 strain from a goose source and reported for the first time, showing a specific structure. Conjugation experiments revealed that the IncHI2 plasmid was conjugatable, and the horizontal propagation of the plasmid led to the rapid propagation of NDM in the same and different strains. This study revealed that waterfowl, as a potential transmission factor for carbapenem-resistant blaNDM-1, poses a threat to human health.