Candida auris inpatient screening in collaboration with the public health department

Candida auris is a multidrug-resistant fungal pathogen that is associated with nosocomial outbreaks in patients with extensive health care exposure and treatment outside the United States. The Ohio Department of Health recommends C auris screening in high-risk patients. However, this can be operationally difficult for many health care facilities. This report describes a C auris and carbapenem-resistant Enterobacterales inpatient screening program done in collaboration with state public health.

Carbapenem use in extended-spectrum cephalosporin-resistant Enterobacterales infections in US hospitals and influence of IDSA guidance: a retrospective cohort study

BACKGROUND

Disparate and rapidly changing practice recommendations from major professional infectious diseases societies for managing non-severe infections caused by extended-spectrum β-lactamase-producing Enterobacterales might hamper carbapenem stewardship. We aimed to understand the real-world management of extended-spectrum cephalosporin-resistant (ECR) Enterobacterales infections in US hospitals and factors influencing preference for carbapenems over alternative treatments.

METHODS

This retrospective cohort study included adults (aged ≥18 years) admitted to hospital with ECR Enterobacterales infections in the PINC AI database. Antibiotic regimens were assessed during empirical and targeted treatment periods and by infection severity and site. Likelihood of receiving targeted carbapenems over time and before or after initial release of the Infectious Diseases Society of America (IDSA) guidance on Sept 8, 2020, was established with generalised estimating equations controlling for patient, hospital, and temporal confounders.

FINDINGS

Between Jan 1, 2018, and Dec 31, 2021, 30 041 inpatient encounters with ECR Enterobacterales infections were identified at 168 US hospitals, of which 16 006 (53·3%) encounters were in women and 14 035 (46·7%) were in men, with a mean age of 67·3 years (SD 15·1). Although few patients received carbapenems empirically (5324 [17·7%] of 30 041), many did so as targeted treatment (17 518 [58·3%] of 30 041), including subgroups of patients without septic shock (3031 [45·6%] of 6651) and patients with urinary tract infections without septic shock (1845 [46·8%] of 3943) in whom specific narrower-spectrum alternatives were active. Transitions from non-carbapenem to carbapenem antibiotics occurred most often on the day that the ECR phenotype was reported, regardless of illness severity. Carbapenems were the predominant choice to treat ECR Enterobacterales infections over time (adjusted odds ratio 1·00 [95% CI 1·00-1·00]), with no additional immediate change (1·07 [0·95-1·20]) or sustained change (0·99 [0·98-1·00]) after IDSA guidance release.

INTERPRETATION

High carbapenem use in targeting non-severe ECR Enterobacterales infections in US hospitals predates 2020 IDSA guidance and has persisted thereafter. Efforts to increase awareness and implementation of recommendations among clinicians to use carbapenem-sparing alternatives in ECR Enterobacterales infections might decrease global carbapenem selective pressure.

FUNDING

US National Institutes of Health Intramural Research Program, National Institute of Allergy and Infectious Diseases, and US Food and Drug Administration.

Horizontal Gene Transfer of blaNDM-5 Among Three Different Enterobacteriaceae Species Isolated from a Single Patient

BACKGROUND

In this study, Escherichia coli, Klebsiella oxytoca, and Citrobacter amalonaticus carrying blaNDM-5 were isolated from a single patient.

METHODS

The antibiotic susceptibility of the isolates was evaluated by using E-test and agar dilution methods, and blaNDM-5 was identified in genomic and plasmid DNA by using polymerase chain reaction and sequencing. Whole genome sequencing and de novo assembly were used for species characterization, resistance gene identification, and plasmid analysis.

RESULTS

All three species had identical plasmids, which were similar to pEC463-NDM5, a plasmid harboring blaNDM-5. Transconjugation experiments confirmed the horizontal gene transfer of blaNDM-5, highlighting the need for a close monitoring of Enterobacteriaceae species harboring this gene.

CONCLUSIONS

This study conclusively demonstrates the propensity for horizontal gene transfer of blaNDM-5 among Enterobacteriaceae species, underlining the importance of vigilant monitoring to combat antibiotic resistance.

Cefoperazone targets D-alanyl-D-alanine carboxypeptidase (DAC) to control Morganella morganii-mediated infection: a subtractive genomic and molecular dynamics approach

Morganella morganii is a Gram-negative bacterial pathogen that causes bacteremia, urinary tract infections, intra-abdominal infections, chorioamnionitis, neonatal sepsis, and newborn meningitis. To control this bacterial pathogen a total of 3565 putative proteins targets in Morganella morganii were screened using comparative subtractive analysis of biochemical pathways annotated by the KEGG that did not share any similarities with human proteins. One of the targets, D-alanyl-D-alanine carboxypeptidase DacB [Morganella] was observed to be implicated in the majority of cell wall synthesis pathways, leading to its selection as a novel pharmacological target. The drug that interacted optimally with the identified target was observed to be Cefoperazone (DB01329) with the estimated free energy of binding -8.9 Kcal/mol. During molecular dynamics simulations; it was observed that DB01328-2exb and DB01329-2exb complexes showed similar values as the control FMX-2exb complex near 0.2 nm with better stability. Furthermore, MMPBSA total free energy calculation showed better binding energy than the control complex for DB01329-2exb interaction i.e. -31.50 (±0.93) kcal/mol. Our presented research suggested that D-alanyl-D-alanine carboxypeptidase DacB could be a therapeutic target and cefoperazone could be a promising ligand to inhibit the D-alanyl-D-alanine carboxypeptidase DacB protein of Morganella morganii. To identify prospective therapeutic and vaccine targets in Morganella morganii, this is the first computational and subtractive genomics investigation of various metabolic pathways exploring other therapeutic targets of Morganella morganii. In vitro/in vivo experimental validation of the identified target D-alanyl-D-alanine carboxypeptidase and the design of its inhibitors is suggested to figure out the best dose, the drug's effectiveness, and its toxicity.Communicated by Ramaswamy H. Sarma.

Antimicrobial Susceptibility and Genetic Epidemiology of Extended-Spectrum β-Lactamase-Positive Enterobacterales Clinical Isolates in Central Poland

The extended-spectrum β-lactamases (ESβLs) are bacterial enzymes capable of hydrolyzing penicillins, cephalosporins, and aztreonam. The prevalence of ESβL is increasing among clinically significant microorganisms worldwide, drastically reducing the therapeutic management of infectious diseases. The study aimed to determine the drug susceptibility of ESβL-positive clinical isolates acquired from patients hospitalized in Lodz, central Poland, and analyze the prevalence of specific genes, determining acquired resistance in these bacteria. The samples of ESβL-positive clinical isolates were gathered in 2022 from medical microbiological laboratories in the city of Lodz, central Poland. The strains were subjected to biochemical identification and antimicrobial susceptibility testing following EUCAST guidelines. The presence of studied genes (blaCTX-M, blaSHV, blaTEM, blaPER, blaVEB) was confirmed by PCR. Over 50% of studied isolates were resistant to gentamicin, cefepime, ceftazidime and ciprofloxacin. The most common ESβL gene was blaCTX-M. In most isolates, the resistance genes occurred simultaneously. The blaPER was not detected in any of the tested strains. ESβL-producing strains are largely susceptible to the currently available antibiotics. The observation of the coexistence of different genes in most clinical isolates is alarming.

Mutation Rate of AmpC β-Lactamase-Producing Enterobacterales and Treatment in Clinical Practice: A Word of Caution

In a retrospective multicenter study of 575 patients with bloodstream infections or pneumonia due to wild-type AmpC β-lactamase-producing Enterobacterales, species with low in vitro mutation rates for AmpC derepression were associated with fewer treatment failures due to AmpC overproduction (adjusted hazard ratio, 0.5 [95% CI, .2-.9]). However, compared to cefepime/carbapenems, using third-generation cephalosporins as definitive therapy remained associated with this adverse outcome (15% vs 1%).

Carbapenem-resistant Enterobacteriaceae in the livestock, humans and environmental samples around the globe: a systematic review and meta-analysis

Carbapenem-resistant Enterobacteriaceae (CRE) have diminished treatment options causing serious morbidities and mortalities. This systematic review and meta-analysis assessed the prevalence and associated factors of Enterobacteriaceae infections in clinical, livestock and environmental settings globally. The population intervention comparison and outcome strategy was used to enroll studies using the preferred reporting system for systematic review and meta-analysis to include only cross-sectional studies. Search engines used to retrieve articles included journal author name estimator, PubMed, Google Scholar and African Journals Online (AJOL). The Newcastle-Ottawa scale was used to assess the quality of studies. Sixteen articles from 2013 to 2023 in Africa, Asia, Europe and South America were studied. The pooled prevalence of CRE was 43.06% (95% CI 21.57-66.03). Klebsiella pneumoniae (49.40%), Escherichia coli (26.42%), and Enterobacter cloacae (14.24%) were predominant. Klebsiella pneumoniae had the highest resistance with the blaKPC-2 in addition to blaNDM, blaOXA-48, blaIMP and blaVIM. The blaKPC-2 genes occurrence was associated with environmental (P-value < 0.0001) and South American studies (P-value < 0.0001), but there was no difference in the trends over time (P-value = 0.745). This study highlights the high rates of CRE infections, particularly within blaKPC production. Monitoring and surveillance programs, research and infection control measures should be strengthened. Additionally, further studies are needed to explore the mechanisms driving the predominance of specific bacterial species and the distribution of resistance genes within this bacterial family.

Edwardsiella tarda Attenuates Virulence upon Oxytetracycline Resistance

The relationship between antibiotic resistance and bacterial virulence has not yet been fully explored. Here, we use Edwardsiella tarda as the research model to investigate the proteomic change upon oxytetracycline resistance (LTB4-ROTC). Compared to oxytetracycline-sensitive E. tarda (LTB4-S), LTB4-ROTC has 234 differentially expressed proteins, of which the abundance of 84 proteins is downregulated and 15 proteins are enriched to the Type III secretion system, Type VI secretion system, and flagellum pathways. Functional analysis confirms virulent phenotypes, including autoaggregation, biofilm formation, hemolysis, swimming, and swarming, are impaired in LTB4-ROTC. Furthermore, the in vivo bacterial challenge in both tilapia and zebrafish infection models suggests that the virulence of LTB4-ROTC is attenuated. Analysis of immune gene expression shows that LTB4-ROTC induces a stronger immune response in the spleen but a weaker response in the head kidney than that induced by LTB4-S, suggesting it's a potential vaccine candidate. Zebrafish and tilapia were challenged with a sublethal dose of LTB4-ROTC as a live vaccine followed by LTB4-S challenge. The relative percentage of survival of zebrafish is 60% and that of tilapia is 75% after vaccination. Thus, our study suggests that bacteria that acquire antibiotic resistance may attenuate virulence, which can be explored as a potential live vaccine to tackle bacterial infection in aquaculture.

Using the CLSI rAST breakpoints of Enterobacterales in positive blood cultures

OBJECTIVES

The objective of this study was to provide the clinic with rapid and accurate results of antimicrobial susceptibility testing for the treatment of patients with bloodstream infections. To achieve this, we applied the Clinical and Laboratory Standards Institute (CLSI) blood culture direct rapid antimicrobial susceptibility test (rAST) to assess the susceptibility of the most common Enterobacterales found in blood cultures.

METHODS

In this study, we utilized the CLSI blood culture direct rapid antimicrobial susceptibility test to assess the susceptibility (rAST) of the most common Enterobacterales present in blood cultures. We chose this method for its simplicity in analysis, and our aim was to predict minimum inhibitory concentrations (MICs) using the rAST. As a benchmark, we assumed that Broth Macrodilution method (BMD) results were 100% accurate. For data evaluation, we employed the terms categorical agreement (CA), very major errors (VME), and major errors (ME).

RESULTS

Our findings demonstrate that the CLSI rAST method is reliable for rapidly determining the in vitro susceptibility of Enterobacterales to common antimicrobial drugs in bloodstream infections. We achieved a concordance rate of 90% in classification within a 10-hour timeframe. We identified a total of 112 carbapenem-resistant Enterobacterales (CRE) strains, and there was no significant difference in the detection rate of CRE at 6, 10, and 16 hours. This suggests that CRE can be identified as early as 6 hours.

CONCLUSION

The CLSI rAST is a valuable tool that can be utilized in clinical practice to quickly determine the susceptibility of Enterobacterales to antimicrobial drugs within 10 hours. This capability can greatly assist in the clinical management of patients with bloodstream infections.

In vitro and in vivo activity of ceftazidime/avibactam and aztreonam alone or in combination against mcr-9, serine- and metallo-β-lactamases-co-producing carbapenem-resistant Enterobacter cloacae complex

PURPOSE

Enterobacteriaceae carrying mcr-9, in particularly those also co-containing metallo-β-lactamase (MBL) and TEM type β-lactamase, present potential transmission risks and lack adequate clinical response methods, thereby posing a major threat to global public health. The aim of this study was to assess the antimicrobial efficacy of a combined ceftazidime/avibactam (CZA) and aztreonam (ATM) regimen against carbapenem-resistant Enterobacter cloacae complex (CRECC) co-producing mcr-9, MBL and TEM.

METHODS

The in vitro antibacterial activity of CZA plus ATM was evaluated using a time-kill curve assay. Furthermore, the in vivo interaction between CZA plus ATM was confirmed using a Galleria mellonella (G. mellonella) infection model.

RESULTS

All eight clinical strains of CRECC, co-carrying mcr-9, MBL and TEM, exhibited high resistance to CZA and ATM. In vitro time-kill curve analysis demonstrated that the combination therapy of CZA + ATM exerted significant bactericidal activity against mcr-9, MBL and TEM-co-producing Enterobacter cloacae complex (ECC) isolates with a 100% synergy rate observed in our study. Furthermore, in vivo survival assay using Galleria mellonella larvae infected with CRECC strains co-harboring mcr-9, MBL and TEM revealed that the CZA + ATM combination significantly improved the survival rate compared to the drug-treatment alone and untreated control groups.

CONCLUSION

To our knowledge, this study represents the first report on the in vitro and in vivo antibacterial activity of CZA plus ATM against CRECC isolates co-harboring mcr-9, MBL and TEM. Our findings suggest that the combination regimen of CZA + ATM provides a valuable reference for clinicians to address the increasingly complex antibiotic resistance situation observed in clinical microorganisms.

Ertapenem Versus Meropenem for the Treatment of Extended Spectrum Beta-Lactamase-Producing Enterobacterales Bacteremia in Critically Ill Patients

BACKGROUND

The preferred carbapenem for treatment of infections caused by extended spectrum beta-lactamase-producing Enterobacterales (ESBL-E) in critically ill patients is debated.

OBJECTIVE

The purpose of this study was to evaluate the difference in clinical failure between ertapenem and meropenem for treatment of ESBL-E bacteremia in critically ill patients. Of concern is ertapenem use in hypoalbuminemia given the potential for higher drug clearance.

METHODS

This retrospective, matched cohort study compared critically ill patients treated with ertapenem or meropenem for ESBL-E bacteremia between October 2016 and August 2022. Patients were matched on age, sex, lowest albumin, and in a 1:2 ratio of ertapenem to meropenem. The primary outcome, clinical failure, was a composite of 30-day mortality, antibiotic escalation, and microbiological failure. Secondary outcomes included all-cause readmission and development of superinfection.

RESULTS

Of 54 patients, 18 received ertapenem and 36 meropenem. Most had a urinary infection source (55.6% vs 41.7%, P = 0.393). There was no difference in clinical failure (50.0% vs 38.9%, P = 0.436). Ertapenem patients had antibiotic escalation more often (33.3% vs 2.8%, P = 0.002). There was no difference in 30-day mortality (11.1% vs 27.8%, P = 0.298), microbiological failure (27.8% vs 11.1%, P = 0.142), all-cause readmission (22.2% vs 13.9%, P = 0.461), or development of superinfection (11.1% vs 13.9%, P = 1.000).

CONCLUSION AND RELEVANCE

There was no difference in clinical failure in a small, retrospective cohort of critically ill patients receiving ertapenem or meropenem for ESBL-E bacteremia. Ertapenem may be appropriate in some critically ill and hypoalbuminemic patients, though additional data are needed.

Impact of removing ESBL status labelling from culture reports on the use of carbapenems for non-bacteraemic patients diagnosed with ESBL-positive urinary tract infections

OBJECTIVES

To evaluate carbapenem prescribing rates for initial definitive treatment of urinary tract infections and clinical outcomes before and after removing ESBL status labels on antibiotic susceptibility reports.

METHODS

This was a retrospective cohort study of adult patients treated for at least 48 h for an ESBL-producing/ceftriaxone-resistant Enterobacterales urinary tract infection. ESBL status reporting ceased in September 2022 for a network of seven community hospitals within the USA. The primary endpoint was the rate of carbapenem prescribing for initial definitive treatment of urinary tract infections. Secondary endpoints included total days of therapy for initial definitive treatment with carbapenems, clinical cure rates, time to transition to oral antibiotic therapy for initial definitive treatment, rate of guideline-compliant therapy, rate of relapsed infection within 30 days, 30 day readmission rate, and 30 day all-cause in-hospital mortality.

RESULTS

Of 3055 patients screened, 199 were included in the pre group and 153 were included in the post group. The rate of carbapenem prescribing for initial definitive treatment was 156 patients (78%) in the pre group, compared with 93 patients (61%) in the post group (P = <0.01). Days of therapy for initial definitive therapy with carbapenem was 620 in the pre group compared with 372 in the post group (P < 0.01). There was no difference between other secondary outcomes.

CONCLUSIONS

Removing ESBL status labels from laboratory reports reduced carbapenem use for initial definitive treatment of urinary tract infections from 78% to 61% (P < 0.01) without impacting clinical outcomes.

Interpreting the results of rapid molecular diagnostic tests for carbapenem-resistant Enterobacterales infection: current clinical perspective while waiting for further evidence

INTRODUCTION

Carbapenem-resistant Enterobacterales (CRE) causing severe infections in humans have represented an important challenge for clinicians worldwide during the past two decades.

AREAS COVERED

Novel β-lactams and β-lactam/β-lactamase inhibitor combinations have led to a shift in the first-line approach to the treatment of severe CRE infections from polymyxin-based regimens to treatment with less toxic agents. This new scenario offers the opportunity to apply rapid molecular diagnostic tests for CRE infection to identify different types of carbapenemases. Herein, the authors provide an overview of this subject and follow it with their expert perspectives.

EXPERT OPINION

When considering studies actually measuring the clinical impact of rapid molecular tests in real-life scenarios, high certainty evidence from randomized controlled trials is still limited and not focused on CRE infections. Nonetheless, it is indisputable that rapid molecular tests have been shown to impact early therapeutic choices (in terms of both escalation and de-escalation) when used in real-life settings, thus issues in the clinical interpretation of their results are already relevant. Overall, increased expertise is required for the appropriate interpretation of rapid molecular tests for personalized antibiotic selection by understanding their strengths and limitations.

Whole-Genome Analysis of Extensively Drug-Resistant Enterobacter hormaechei Isolated from a Patient with Non-Hodgkin's Lymphoma

BACKGROUND

Currently, the Enterobacteriaceae species are responsible for a variety of serious infections and are already considered a global public health problem, especially in underdeveloped countries, where surveillance and monitoring programs are still scarce and limited. Analyses were performed on the complete genome of an extensively antibiotic-resistant strain of Enterobater hormaechei, which was isolated from a patient with non-Hodgkin's lymphoma, who had been admitted to a hospital in the city of Manaus, Brazil.

METHODS

Phenotypical identification and susceptibility tests were performed in automated equipment. Total DNA extraction was performed using the PureLink genomic DNA mini-Kit. The genomic DNA library was prepared with Illumina Microbial Amplicon Prep and sequenced in the MiSeq Illumina Platform. The assembly of the whole-genome and individual analyses of specific resistance genes extracted were carried out using online tools and the Geneious Prime software.

RESULTS

The analyses identified an extensively resistant ST90 clone of E. hormaechei carrying different genes, including blaCTX-M-15, blaGES-2, blaTEM-1A, blaACT-15, blaOXA-1 and blaNDM-1, [aac(3)-IIa, aac(6')-Ian, ant(2″)-Ia], [aac(6')-Ib-cr, (qnrB1)], dfrA25, sul1 and sul2, catB3, fosA, and qnrB, in addition to resistance to chlorhexidine, which is widely used in patient antisepsis.

CONCLUSIONS

These findings highlight the need for actions to control and monitor these pathogens in the hospital environment.

Pantoea dispersa peritoneal dialysis catheter-related infection

Enteric gram-negative bacteria-associated peritoneal dialysis (PD) peritonitis is common. These organisms are such as Escherichia coli, Klebsiella and Enterobacter species. Pantoea dispersa belongs to the order Enterobacterales, it has known benefits and a role in agricultural and environmental biotechnology. Pantoea dispersa, although still relatively rare, is being increasingly recognised to cause human infections. We are reporting a case of PD peritonitis caused by Pantoea dispersa in a kidney failure patient on continuous ambulatory peritoneal dialysis (CAPD). His peritonitis was treated well with intraperitoneal antibiotics and the patient can resume his CAPD therapy. The increasing reports of Pantoea dispersa-related human infections warrant concerns, both in immunocompromised and immunocompetent patients.

The impact of colistin-based regimens on mortality compared to other antimicrobials in patients with carbapenem-resistant Enterobacterales bacteremia in South African hospitals: a cross-sectional study

BACKGROUND

Treatment of carbapenem-resistant Enterobacterales (CRE) infections in low-resource settings is challenging particularly due to limited treatment options. Colistin is the mainstay drug for treatment; however, nephrotoxicity and neurotoxicity make this drug less desirable. Thus, mortality may be higher among patients treated with alternative antimicrobials that are potentially less efficacious than colistin. We assessed mortality in patients with CRE bacteremia treated with colistin-based therapy compared to colistin-sparing therapy.

METHODS

We conducted a cross-sectional study using secondary data from a South African national laboratory-based CRE bacteremia surveillance system from January 2015 to December 2020. Patients hospitalized at surveillance sentinel sites with CRE isolated from blood cultures were included. Multivariable logistic regression modeling, with multiple imputations to account for missing data, was conducted to determine the association between in-hospital mortality and colistin-based therapy versus colistin-sparing therapy.

RESULTS

We included 1 607 case-patients with a median age of 29 years (interquartile range [IQR], 0-52 years) and 53% (857/1 607) male. Klebsiella pneumoniae caused most of the infections (82%, n=1 247), and the most common carbapenemase genes detected were blaOXA-48-like (61%, n=551), and blaNDM (37%, n=333). The overall in-hospital mortality was 31% (504/1 607). Patients treated with colistin-based combination therapy had a lower case fatality ratio (29% [152/521]) compared to those treated with colistin-sparing therapy 32% [352/1 086]) (p=0.18). In our imputed model, compared to colistin-sparing therapy, colistin-based therapy was associated with similar odds of mortality (adjusted odds ratio [aOR] 1.02; 95% confidence interval [CI] 0.78-1.33, p=0.873).

CONCLUSION

In our resource-limited setting, the mortality risk in patients treated with colistin-based therapy was comparable to that of patients treated with colistin-sparing therapy. Given the challenges with colistin treatment and the increasing resistance to alternative agents, further investigations into the benefit of newer antimicrobials for managing CRE infections are needed.

Misidentification and misreporting of antibiotic resistance in Kluyvera bacteremia by blood culture molecular identification panels

The use of molecular identification panels has advanced the diagnosis for blood stream infections with fast turnaround time and high accuracy. Yet, this technology cannot completely replace conventional blood culture and standardized antibiotic susceptibility testing (AST) given its limitations and occasional false results. Here we present two cases of bacteremia caused by Kluyvera. Its identification and antibiotic resistance were at least partially mispresented by blood culture molecular identification panels on ePlex, Verigene, and Biofire. The detection of CTX-M resistance marker did not align with the susceptibility to the third generation cephalosporins among a wide range of antibiotics for this organism. Conventional extended-spectrum beta-lactamase (ESBL) testing was used to confirm the absence of ESBL. Caution should be taken when managing cases with CTX-M or ESBL detection in blood culture caused by uncommon pathogens. Conventional culture with microbial identification and standardized AST should continue to be the gold standard for routine patient care.

IMPORTANCE

This is the first report that highlights the limitations of blood culture molecular identification panels on identifying Kluyvera and its associated antibiotic resistance patterns. Both the false identification and overreporting of antibiotic resistance could mislead the treatment for bacteremia caused by this pathogen. Patient isolation could have been avoided due to the lack of extended-spectrum beta-lactamase (ESBL) activity of the organism. This report emphasizes the importance of confirming rapid identification and antibiotic resistance by molecular technologies with standardized methods. It also provides insight into the development of new diagnostic panels.

Acute Encephalopathy in a Patient with Raoultella Ornithinolytica Infection: A Challenging Presentation

Raoultella ornithinolytica is a rare, gram-negative environmental enterobacterium. Although infections in humans caused by R. ornithinolytica are uncommon, there are increasing reports implicating it in urinary tract infections, hepatobiliary infections, and bacteremia, designating it as an emerging pathogen. Its habitat is primarily in aquatic environments and soil, with seafood frequently identified as a potential source of infection. While these infections have predominantly been described in immunocompromised patients previously, our case suggests that advanced age may be a significant risk factor. We describe a case of a 73-year-old man presenting with encephalopathy who then was found to have R. ornithinolytica bacteremia from a genitourinary source. Following antibiotic treatment, the infection resolved and the neurologic symptoms improved. To the best of our knowledge, this is the first documented case in the medical literature of R. ornithinolytica featuring a primary neurologic presentation.

Mortality factors and antibiotic options in carbapenem-resistant Enterobacterales bloodstream infections: Insights from a high-prevalence setting with co-occurring NDM-1 and OXA-48

Bloodstream infections (BSI) caused by carbapenem-resistant Enterobacterales (CRE) are associated with a high mortality rate. This study aimed to investigate factors associated with 14-day mortality and identify a potential treatment option. A retrospective cohort study was conducted on patients with CRE-BSI in Thailand from 2015 to 2020. The multivariate Cox proportional-hazards model was employed to identify factors influencing 14-day mortality. Out of 134 diagnosed cases of CRE-BSI, the all-cause 14-day mortality rate was 35.1%. The most prevalent organism isolated was Klebsiella pneumoniae (85.8%), followed by Escherichia coli (11.9%). Among the 60 isolates tested for carbapenemase genes, the majority exhibited co-occurring blaNDM-1 and blaOXA-48 (51.7%), followed by blaOXA-48 (31.7%) and blaNDM-1 (15.0%). In the multivariate analysis, neutropenia (adjusted hazard ratio [aHR] 2.55; 95% confidence interval [95%CI] 1.28-5.06; p = 0.008), sepsis/septic shock (aHR 3.02; 95%CI 1.33-6.86; p = 0.008), and previous metronidazole exposures (aHR 3.58; 95%CI 1.89-6.71; p < 0.001) were identified as independent factors for 14-day mortality. The fosfomycin-based regimen was found to be protective (aHR 0.37; 95%CI 0.15-0.92; p = 0.032). In patients with CRE-BSI, particularly in regions with a high occurrence of co-occurring blaNDM-1 and blaOXA-48, neutropenia, sepsis/septic shock, and previous metronidazole exposures emerged as independent risk factors for mortality. Moreover, the fosfomycin-based regimen showed an improvement in the survival rate.

Indian consensus on the managemeNt of carbapenem-resistant enterobacterales infection in critically ill patients II (ICONIC II)

INTRODUCTION

The rising challenge of carbapenem-resistant Enterobacterales (CRE) infections in Indian healthcare settings calls for clear clinical guidance on the management of these infections. The Indian consensus on the management of CRE infection in critically ill patients (ICONIC-II) is a follow-up of the ICONIC-I study, which was undertaken in 2019.

AREAS COVERED

A modified Delphi method was used to build expert consensus on CRE management in India, involving online surveys, face-to - face expert meetings, and a literature review. A panel of 12 experts was formed to develop potential clinical consensus statements (CCSs), which were rated through two survey rounds. The CCSs were finalized in a final face-to - face discussion. The finalized CCSs were categorized as consensus, near consensus, and no consensus.

EXPERT OPINION

The outcomes included 46 CCSs (consensus: 40; near consensus: 3; and no consensus: 3). The expert panel discussed and achieved consensus on various strategies for managing CRE infections, emphasizing the significance of existing and emerging resistance mechanisms, prompt and tailored empiric therapy, and use of combination therapies. The consensus statements based on the collective expertise of the panel can potentially assist clinicians in the management of CRE infections that lack high-level evidence.

Harvesting and amplifying gene cassettes confers cross-resistance to critically important antibiotics

Amikacin and piperacillin/tazobactam are frequent antibiotic choices to treat bloodstream infection, which is commonly fatal and most often caused by bacteria from the family Enterobacterales. Here we show that two gene cassettes located side-by-side in and ancestral integron similar to In37 have been "harvested" by insertion sequence IS26 as a transposon that is widely disseminated among the Enterobacterales. This transposon encodes the enzymes AAC(6')-Ib-cr and OXA-1, reported, respectively, as amikacin and piperacillin/tazobactam resistance mechanisms. However, by studying bloodstream infection isolates from 769 patients from three hospitals serving a population of 1.2 million people in South West England, we show that increased enzyme production due to mutation in an IS26/In37-derived hybrid promoter or, more commonly, increased transposon copy number is required to simultaneously remove these two key therapeutic options; in many cases leaving only the last-resort antibiotic, meropenem. These findings may help improve the accuracy of predicting piperacillin/tazobactam treatment failure, allowing stratification of patients to receive meropenem or piperacillin/tazobactam, which may improve outcome and slow the emergence of meropenem resistance.

Carriage of antimicrobial-resistant Enterobacterales among pregnant women and newborns in Amhara, Ethiopia

OBJECTIVES

Infections are one of the most common causes of neonatal mortality, and maternal colonization has been associated with neonatal infection. In this study, we sought to quantify carriage prevalence of extended-spectrum-beta-lactamase (ESBL) -producing and carbapenem-resistant Enterobacterales (CRE) among pregnant women and their neonates and to characterize risk factors for carriage in rural Amhara, Ethiopia.

METHODS

We conducted a prospective cohort study nested in the Birhan field site. We collected rectal and vaginal samples from 211 pregnant women in their third trimester and/or during labor/delivery and perirectal or stool samples from 159 of their neonates in the first week of life.

RESULTS

We found that carriage of ESBL-producing organisms was fairly common (women: 22.3%, 95% CI: 16.8-28.5; neonates: 24.5%, 95% CI: 18.1-32.0), while carriage of CRE (women: 0.9%, 95% CI: 0.1-3.4; neonates: 2.5%, 95% CI: 0.7-6.3) was rare. Neonates whose mothers tested positive for ESBL-producing organisms were nearly twice as likely to also test positive for ESBL-producing organisms (38.7% vs 21.1%, P-value = 0.06). Carriage of ESBL-producing organisms was also associated with Woreda (district) of sample collection and recent antibiotic use.

CONCLUSION

Understanding carriage patterns of potential pathogens and antibiotic susceptibility among pregnant women and newborns will inform local, data-driven recommendations to prevent and treat neonatal infections.