Epidemiological situation, laboratory capacity and preparedness for carbapenem-resistant Acinetobacter baumannii in Europe, 2019

Characterization and risk-quantification of antibiotic resistome in grain-based and non-grain cropping soils

Microbial contamination in soils, encompassing human bacterial pathogens (HBPs), antibiotic resistance genes (ARGs), and virulence factor genes (VFGs), poses a significant threat to human health via the food chain. Currently, there is a lack of comprehensive assessments of microbial contamination and associated health risks of ARGs in agricultural soils. In this study, metagenomic sequencing was used to evaluate microbial contamination in grain-based cropping soils (rice cultivation) and non-grain cropping soils (vegetable cultivation and aquaculture). The results showed that the diversity and abundance of HBPs and VFGs were significantly higher in non-grain soils. Further resistome analysis revealed higher abundances of high-risk (from 0.014 to 0.018-0.023) and "last-resort" ARGs (from 0.007 to 0.034-0.046) in non-grain soils. Besides ARGs abundance, health risk quantification revealed that non-grain soils exhibited 1.49-2.14-fold greater ARG-related risks than grain-based soils. Additionally, stronger network associations were found between HBPs, ARGs, and mobile genetic elements (MGEs) in non-grain soils. This study indicated that the non-grain cropping pattern of soils elevated the risk of microbial contamination and ARGs health risk, which provided an important basis for accurately quantifying the risk of microbial contamination in different agricultural soils.

Development of a novel multi-epitope subunit mRNA vaccine candidate to combat Acinetobacter baumannii

Acinetobacter baumannii, an opportunistic bacterium prevalent in various environment, is a significant cause of nosocomial infections in ICUs. As the causative agent of pneumonia, septicemia, and meningitis, A. baumannii typically exhibits multidrug resistance and is associated with poor prognosis, thus led to a challenge for researchers in developing new treatment and prevention methods. This study involved the development of a novel multi-epitope mRNA vaccine for A. baumannii and validation of in silico approaches was conducted. We screened 11 immunodominant epitopes for cytotoxic T cells, 5 for helper T cells, and 10 for Linear B-cell based on promising candidate proteins omp33-36, ompA and ompW, the selection of these three proteins is based on reverse vaccinology screening and previous work by other researchers. All predicted epitopes demonstrated strong antigenicity, immunogenicity without posing any potential harm to humans. Additionally, high conservancy is required to cover different strains. All epitopes, as well as adjuvants, were constructed into a final vaccine, which was further assessed by calculating its physicochemical properties. Next, we docked the vaccine protein with immune receptors and analyzed the complexes with dynamic simulations to evaluate its affinity to receptors. At last, the constructed sequence is translated to an mRNA sequence. The results indicated the constructed vaccine is capability of eliciting robust humoral and cellular immune responses, making it a promising candidate for protection against the targeted pathogen.

Potentially effective antimicrobial treatment for pneumonia caused by isolates of carbapenem-resistant and extensively drug-resistant Acinetobacter baumannii complex species: what can we expect in the future?

INTRODUCTION

Acinetobacter baumannii complex (Abc) is currently a significant cause of difficult-to-treat pneumonia. Due to the high prevalence rates of carbapenem- and extensively drug-resistant (CR, XDR) phenotypes, limited antibiotic options are available for the effective treatment of pneumonia caused by CR/XDR-Abc.

AREAS COVERED

In vitro susceptibility data, relevant pharmacokinetic profiles (especially the penetration ratios from plasma into epithelial-lining fluid), and pharmacodynamic indices of key antibiotics against CR/XDR-Abc are reviewed.

EXPERT OPINION

Doubling the routine intravenous maintenance dosages of conventional tigecycline (100 mg every 12 h) and minocycline (200 mg every 12 h) might be recommended for the effective treatment of pneumonia caused by CR/XDR-Abc. Nebulized polymyxin E, novel parenteral rifabutin BV100, and new polymyxin derivatives (SPR206, MRX-8, and QPX9003) could be considered supplementary combination options with other antibiotic classes. Regarding other novel antibiotics, the potency of sulbactam-durlobactam (1 g/1 g infused over 3 h every 6 h intravenously) combined with imipenem-cilastatin, and the β-lactamase inhibitor xeruborbactam, is promising. Continuous infusion of full-dose cefiderocol is likely an effective treatment regimen for CR/XDR-Abc pneumonia. Zosurabalpin exhibits potent anti-CR/XDR-Abc activity in vitro, but its practical use in clinical therapy remains to be evaluated. The clinical application of antimicrobial peptides and bacteriophages requires validation.

Clinical impact of active screening cultures for carbapenem-resistant Acinetobacter baumannii: A systematic review and meta-analysis

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a significant health care-associated infection carrying substantial mortality. We assessed the clinical impact of active screening cultures for CRAB.

METHODS

A systematic review and meta-analysis, aiming to answer 2 questions: (1) Does screening versus no screening improve clinical outcomes? (2) Does positive screening ("CRAB carrier") predict CRAB infections? We searched the literature until January 2024 for comparative studies reporting clinical outcomes (mortality, invasive CRAB infections).

RESULTS

Of 5,407 screened publications, 9 studies (10,865 individuals) were included. Invasive CRAB infection rate was significantly higher among CRAB carriers (OR 11.14, 95% CI 4.95-25.05, with substantial heterogeneity stemming from size rather than direction of the effect). Negative predictive value of noncarriage for invasive infection was 97%. CRAB bloodstream infection rate was significantly higher among carriers (odds ratio 16.23, 95% confidence interval 2.9-110.08). No difference was demonstrated between the groups for CRAB ventilator-associated pneumonia, length of stay, and mortality. Only 1 study reported outcomes for study question #1.

CONCLUSIONS

Data to support active CRAB screening are scarce regarding its clinical benefit for patients. Positively screened patients are at significantly higher risk for invasive CRAB infections, with high negative predictive value for noncarriage. This did not translate to reduced mortality.

Global emergence of double and multi-carbapenemase producing organisms: epidemiology, clinical significance, and evolutionary benefits on antimicrobial resistance and virulence

Redundant carbapenemase-producing (RCP) bacteria, which carry double or multiple carbapenemases, represent a new and concerning phenomenon. The objective of this study is to conduct a comprehensive analysis of the epidemiology and genetic mechanisms of RCP strains to support targeted surveillance and control measures. A retrospective analysis was conducted using surveillance data from 277 articles. Statistical analysis was performed to determine and evaluate species prevalence, proportions of carbapenemases, antibiotic susceptibility profiles, sample information, and patient outcomes. Complete plasmid sequencing data were utilized to investigate potential antimicrobial resistance or virulence advantages that strains may gain from acquiring redundant carbapenemases. RCP bacteria are widely distributed globally, and their prevalence is increasing over time. Several countries, including China, India, Iran, Turkey, and South Korea, have reported more than 100 RCP strains. The most commonly reported RCP species are Klebsiella pneumoniae and Acinetobacter baumannii, which exhibit varying proportions of carbapenemase combinations. Certain species-carbapenemase combinations, such as K. pneumoniae carrying New Delhi metallo-β-lactamase (NDM) + oxacillinase (OXA) (56.76%) and K. pneumoniae carbapenemase (KPC) + Verona integron-encoded metallo-β-lactamase (VIM) (50.00%) carbapenemases, are associated with high mortality rates. In patients with RCP strains isolated from the bloodstream and respiratory system, the mortality rates are 58.70% and 69.23%, respectively. Analysis of plasmids from RCP strains suggests that they may acquire additional antibiotic resistance phenotypes and virulence factors. Carbapenem-resistant bacteria carrying redundant carbapenemases pose a significant global health threat. This study provides valuable insights into the epidemiology and genetic mechanisms of these bacteria, supporting the development of effective control and prevention strategies to mitigate their transmission.IMPORTANCEThis study examined the global distribution patterns of 1,780 bacteria with double or multiple carbapenemases from 277 articles and assessed their clinical impact. The presence of multiple carbapenemases increases the chances of co-resistance to other classes of antibiotics and more virulence factors, further complicating the clinical management of infections.

Molecular epidemiology and clinical significance of carbapenemase genes in carbapenem-resistant Acinetobacter baumannii isolates in southern Poland

INTRODUCTION

A complex interplay between Acinetobacter spp., patients, and the environment has made it increasingly difficult to optimally treat patients infected with Acinetobacter spp., mainly due to rising antimicrobial resistance and challenges with surveillance.

OBJECTIVES

This study evaluated carbapenem‑resistant A. baumannii (CRAB) isolates to determine their resistance profiles and the presence of specific β‑lactamases to inform CRAB surveillance upon hospital admission and regional empiric antibiotic therapies.

PATIENTS AND METHODS

The study was conducted at 4 hospitals in southern Poland between June and December 2022. Only health care-associated infections caused by A. baumannii were considered. A total of 82 CRAB isolates were included in the analysis. Species identification was performed by matrix‑assisted laser desorption / ionization time‑of‑flight mass spectrometry, antimicrobial susceptibility was determined phenotypically, and polymerase chain reactions were carried out to identify the resistance genes.

RESULTS

Depending on the hospital, the incidence of CRAB infections varied from 428.6 to 759.5 per 10 000 admissions in intensive care units (ICUs), and from 0.3 to 21 per 10 000 admissions in non‑ICUs. CRAB antibiotic susceptibility was the highest for cefiderocol (100%), colistin (96%), tigecycline (77%), gentamicin (51%), and ampicillin / sulbactam (36%). The most prevalent blaOXA genes were blaOXA‑66‑1 (95%) and blaOXA‑40 (71%), and additionally the extended‑spectrum β‑lactamase gene blaTEM‑1 (41%).

CONCLUSION

An unexpectedly high incidence of CRAB infections occurred in Polish hospitals. There is a need for effective CRAB prevention and control that includes effective hospital screening, national surveillance, and improved treatment options.

The molecular detection of carbapenem markers with a two-levels amplification screening protocol: epidemiological and resistome insights

Objectives

Carbapenem-resistance is a challenging healthcare concern and require specific stewardship programs. Monitoring workflows include the identification from surveillance samples, such as rectal swabs. Although culture assays represent the gold standard, data report a significant effectiveness in detecting carbapenemases genes directly from rectal swabs. The aim of this study was to evaluate the REALQUALITY Carba-Screen kit (AB ANALITICA, Padova, Italy) in detecting carbapenemases genes directly from rectal swabs, also comparing its effectiveness to culture assays results. A next-generation sequencing (NGS) was performed to investigate the positive samples about resistance markers and sequence type (ST).

Methods

A number of 136 rectal swabs were collected from the University Hospital Policlinico of Catania critical wards. The samples simultaneously underwent culture and molecular assays (REALQUALITY Carba-Screen kit). The molecular method included two-steps. The first step (1 h and 6 min) rapidly excluded negative samples, while the second one (1 h and 6 min) included only positive samples for a resistance confirmation. All the positive culture samples underwent NGS analysis.

Results

Statistical evaluations demonstrated high sensitivity (100%) and detection rates (92.6%) for the REALQUALITY Carba-Screen kit, which mostly correlated to the standard workflow. All the culture positive results matched the positive molecular results, which were mainly confirmed by the NGS resistome analysis. The identified ST appeared to be diversified and different from the clinically significative strains of the same setting, furnishing interesting epidemiological evidence.

Conclusion

The molecular detection allowed a coordinate approach in a high-prevalence multi-drug-resistance area. The rapid identification with a multi-step procedure accelerated the infection control procedures, while the preliminary negative results reduced the overtreatment episodes. The molecular method efficacy was confirmed through the NGS. In conclusion, the molecular screening could initially lead to a more conservative approach, which may be reevaluated after a culture result about the microorganisms' identification and susceptibility profile.

Molecular characterisation of colistin and carbapenem-resistant clinical isolates of Acinetobacter baumannii from Southeast Europe

OBJECTIVES

To characterise 11 colistin- and carbapenem-resistant Acinetobacter baumannii isolates recently emerging in hospital settings.

METHODS

A. baumannii isolates were collected from hospitalised patients under colistin treatment in three countries of Southeast Europe: Turkey, Croatia, and Bosnia and Herzegovina. Isolates were identified using molecular methods.

RESULTS

Isolates from Turkey and Croatia belong to the sequence types ST195 or ST281 of the clone lineage 2, while the single isolate from Bosnia and Herzegovina belongs to the ST231 of clone lineage 1. All isolates turned out to be highly resistant to colistin (MIC ≥ 16 mg/L) and have point mutations in pmrCAB operon genes. The colistin-resistant isolate from Bosnia and Herzegovina had a unique P170L point mutation in the pmrB gene and the R125H point mutation in the pmrC gene. The L20S mutation in the pmrA gene was detected only in isolates from Croatia and has never been reported before in isolates from this country.

CONCLUSION

Colistin resistance in A. baumannii in hospitalised patients receiving colistin treatment is a result of chromosomal mutations. The pattern of point mutations in pmrCAB genes suggests a spread of specific colistin-resistant isolates within the hospital.

Geographic patterns of Acinetobacter baumannii and carbapenem resistance in the Asia-Pacific Region: results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program, 2012-2019

OBJECTIVES

This study aimed to investigate the geographic distribution of carbapenem-resistant Acinetobacter baumannii (CR-AB) isolates in the Asia-Pacific region.

METHODS

We collected A. baumannii isolates using the Antimicrobial Testing Leadership and Surveillance program from 2012 to 2019. The minimum inhibitory concentrations (MICs) of the isolates were determined using the broth microdilution method. The major carbapenemase genes were identified using multiplex polymerase chain reaction assays for the isolates collected between 2012 and 2014. CR-AB was defined as isolates with meropenem MICs ≥8 mg/l.

RESULTS

In total, 2674 A. baumannii isolates were collected from 13 countries, of which 1918 (71.7%) were CR-AB. The carbapenem resistance rates among A. baumannii isolates were as low as 2.8% and 6.5% in Japan and Australia, respectively, but as high as 88% and 87.2% in South Korea and India, respectively. Of the 232 CR-AB isolates that underwent carbapenemase gene screening, 224 (96.6%) harbored at least one carbapenemase gene. A total of 226 carbapenemase genes were detected, with bla_OXA-23 (94.7%, 214/226) being the most dominant, followed by bla_OXA-72 (2.7%, 6/226), bla_OXA-58 (2.2%, 5/226), and bla_NDM-1 (0.4%, 1/226). CR-AB isolates had >80% resistance to amikacin, ampicillin/sulbactam, cefepime, ceftazidime, ciprofloxacin, levofloxacin, and piperacillin/tazobactam. The rates of CR-AB resistance to minocycline and colistin were 7.2% (31/429) and 1.7% (23/1368). For cefoperazone/sulbactam and tigecycline, 50.2% (527/1049) and 93.3% (1789/1918) of CR-AB isolates had an MIC ≤16 mg/l and ≤2 mg/l, respectively.

CONCLUSION

The prevalence of carbapenem resistance in A. baumannii showed significant differences among countries in the Asia-Pacific region, and the treatment options were limited.

Multidrug-resistant Gram-negative bacilli recovered from respiratory and blood specimens from adults: the ATLAS surveillance program in European hospitals, 2018-2020

The population of people ≥65 years of age is increasing in Europe. Pneumonia is a prominent cause of infection in this age group. These patients may be at heightened risk of infection caused by multidrug-resistant (MDR) organisms owing to their frequent and prolonged contact with healthcare facilities as well as frequent exposure to antimicrobials and medical devices. However, ATLAS surveillance data did not demonstrate any difference in the incidence of MDR Gram-negative pathogens among patients ≥65 years of age and those aged <65 years. Higher rates of carbapenem-resistant Enterobacterales (CRE) and MDR Pseudomonas aeruginosa were observed in patients aged 18-64 years (10.7% and 32.3%, respectively) than in patients aged ≥65 years (5.0% and 25.4%, respectively). Significant therapeutic gaps were identified for CRE, carbapenem-resistant Acinetobacter baumannii (65.9% of isolates tested) and MDR P. aeruginosa, which continue to be prevalent in European hospitals. Among the antimicrobials evaluated, only colistin provided >75% in vitro coverage for these pathogens.

Increasing number of cases and outbreaks caused by Candida auris in the EU/EEA, 2020 to 2021

The number of cases of Candida auris infection or carriage and of countries reporting cases and outbreaks increased in the European Union and European Economic Area during 2020 and 2021. Eight countries reported 335 such cases in 2020 and 13 countries 655 cases in 2021. Five countries experienced outbreaks while one country reported regional endemicity. These findings highlight the need for adequate laboratory capacity and surveillance for early detection of C. auris and rapid implementation of control measures.

Large increase in bloodstream infections with carbapenem-resistant Acinetobacter species during the first 2 years of the COVID-19 pandemic, EU/EEA, 2020 and 2021

Recent data from the European Antimicrobial Resistance Surveillance Network (EARS-Net) show a large increase of +57% in Acinetobacter species bloodstream infections in the European Union and European Economic Area in the first years of the COVID-19 pandemic (2020-2021) compared with 2018-2019. Most were resistant to carbapenems, from intensive care units, and in countries with ≥ 50% carbapenem resistance in Acinetobacter spp. in 2018-2019. This highlights the requirement for reinforced Acinetobacter preparedness and infection prevention and control in Europe.

Is It Possible to Eradicate Carbapenem-Resistant Acinetobacter baumannii (CRAB) from Endemic Hospitals?

Background: Despite the global efforts to antagonize carbapenem-resistant Acinetobacter baumannii (CRAB) spreading, it remains an emerging threat with a related mortality exceeding 40% among critically ill patients. The purpose of this review is to provide evidence concerning the best infection prevention and control (IPC) strategies to fight CRAB spreading in endemic hospitals. Methods: The study was a critical review of the literature aiming to evaluate all available studies reporting IPC measures to control CRAB in ICU and outside ICU in both epidemic and endemic settings in the past 10 years. Results: Among the 12 included studies, the majority consisted of research reports of outbreaks mostly occurred in ICUs. The reported mortality reached 50%. Wide variability was observed related to the frequency of application of recommended CRAB IPC measures among the studies: environmental disinfection (100%); contact precautions (83%); cohorting staff and patients (75%); genotyping (66%); daily chlorhexidine baths (58%); active rectal screening (50%); closing or stopping admissions to the ward (33%). Conclusions: Despite effective control of CRAB spreading during the outbreaks, the IPC measures reported were heterogeneous and highly dependent on the different setting as well as on the structural characteristics of the wards. Reinforced ‘search and destroy’ strategies both on the environment and on the patient, proved to be the most effective measures for permanently eliminating CRAB spreading.

5NosoAE: a web server for nosocomial bacterial antibiogram investigation and epidemiology survey

5NosoAE is a webserver that can be used for nosocomial bacterial analysis including the identification of similar strains based on antimicrobial resistance profiles (antibiogram) and the spatiotemporal distribution visualization and phylogenetic analysis of identified strains with similar antibiograms. The extensive use of antibiotics has caused many pathogenic bacteria to develop multiple drug resistance, resulting in clinical infection treatment challenges and posing a major threat to global public health. Relevant studies have investigated the key determinants of antimicrobial resistance in the whole-genome sequence of bacteria. However, a web server is currently not available for performing large-scale strain searches according to antimicrobial resistance profiles and visualizing epidemiological information including the spatiotemporal distribution, antibiogram heatmap, and phylogeny of identified strains. Here, we implemented these functions in the new server, referred to as 5NosoAE. This server accepts the genome sequence file in the FASTA format of five nosocomial bacteria, namely Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecium and Staphylococcus aureus for query. All visualizations are implemented in JavaScript and PHP. This server will be useful for physicians and epidemiologists involved in research on infectious disease. The 5NosoAE platform is available at https://nosoae.imst.nsysu.edu.tw.

The challenge of preventing and containing outbreaks of multidrug-resistant organisms and Candida auris during the coronavirus disease 2019 pandemic: report of a carbapenem-resistant Acinetobacter baumannii outbreak and a systematic review of the literature

BACKGROUND

Despite the adoption of strict infection prevention and control measures, many hospitals have reported outbreaks of multidrug-resistant organisms (MDRO) during the Coronavirus 2019 (COVID-19) pandemic. Following an outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) in our institution, we sought to systematically analyse characteristics of MDRO outbreaks in times of COVID-19, focussing on contributing factors and specific challenges in controlling these outbreaks.

METHODS

We describe results of our own CRAB outbreak investigation and performed a systematic literature review for MDRO (including Candida auris) outbreaks which occurred during the COVID-19 pandemic (between December 2019 and March 2021). Search terms were related to pathogens/resistance mechanisms AND COVID-19. We summarized outbreak characteristics in a narrative synthesis and contrasted contributing factors with implemented control measures.

RESULTS

The CRAB outbreak occurred in our intensive care units between September and December 2020 and comprised 10 patients (thereof seven with COVID-19) within two distinct genetic clusters (both ST2 carrying OXA-23). Both clusters presumably originated from COVID-19 patients transferred from the Balkans. Including our outbreak, we identified 17 reports, mostly caused by Candida auris (n = 6) or CRAB (n = 5), with an overall patient mortality of 35% (68/193). All outbreaks involved intensive care settings. Non-adherence to personal protective equipment (PPE) or hand hygiene (n = 11), PPE shortage (n = 8) and high antibiotic use (n = 8) were most commonly reported as contributing factors, followed by environmental contamination (n = 7), prolonged critical illness (n = 7) and lack of trained HCW (n = 7). Implemented measures mainly focussed on PPE/hand hygiene audits (n = 9), environmental cleaning/disinfection (n = 9) and enhanced patient screening (n = 8). Comparing potentially modifiable risk factors and control measures, we found the largest discrepancies in the areas of PPE shortage (risk factor in 8 studies, addressed in 2 studies) and patient overcrowding (risk factor in 5 studies, addressed in 0 studies).

CONCLUSIONS

Reported MDRO outbreaks during the COVID-19 pandemic were most often caused by CRAB (including our outbreak) and C. auris. Inadequate PPE/hand hygiene adherence, PPE shortage, and high antibiotic use were the most commonly reported potentially modifiable factors contributing to the outbreaks. These findings should be considered for the prevention of MDRO outbreaks during future COVID-19 waves.

Activity of Sulbactam-Durlobactam and Comparators Against a National Collection of Carbapenem-Resistant Acinetobacter baumannii Isolates From Greece

Background

Acinetobacter baumannii is a leading cause of healthcare-associated infections worldwide, due to both its persistence in the hospital setting and ability to acquire high levels of antibiotic resistance. Carbapenem-resistant A. baumannii isolates (CRAB) limit the activity of current antimicrobial regimens and new alternatives or adjuncts to traditional antibiotics are urgently needed. Durlobactam is a novel broad-spectrum inhibitor of serine-type β-lactamases that restores sulbactam (SUL) activity against A. baumannii. The sulbactam-durlobactam (SD) combination has recently completed Phase 3 testing in the global ATTACK trial.

Objectives

The aim of this study is to evaluate the in vitro activity of SD versus comparators against a representative nationwide collection of CRAB isolates.

Methods

One hundred ninety CRAB isolates were collected from clinical samples of patients hospitalized in 11 hospitals throughout Greece during 2015. In vitro activities of SD and comparators (SUL alone, amikacin, minocycline, imipenem, meropenem, colistin, SD and imipenem combined with SD) were determined by broth microdilution.

Results

Durlobactam restored sulbactam activity against the majority of the strains tested, with SD exhibiting the lowest MIC₉₀ (8 μg/ml) relative to the other single comparators tested; 87.9% of the isolates had SD MICs ≤4/4 µg/ml. The most active comparator was colistin (MIC₉₀ = 16 μg/ml). The addition of imipenem further lowered the MIC₉₀ of SD by one two-fold dilution.

Conclusions

This study demonstrated the potential utility of SD for the treatment of infections caused by A. baumannii. If its clinical efficacy is confirmed, SD may be an important therapeutic option for CRAB infections.

A Study in a Regional Hospital of a Mid-Sized Spanish City Indicates a Major Increase in Infection/Colonization by Carbapenem-Resistant Bacteria, Coinciding with the COVID-19 Pandemic

Bacterial resistance to antibiotics has proven difficult to control over the past few decades. The large group of multidrug-resistant bacteria includes carbapenemase-producing bacteria (CPB), for which limited therapeutic options and infection control measures are available. Furthermore, carbapenemases associate with high-risk clones that are defined by the sequence type (ST) to which each bacterium belongs. The objectives of this cross-sectional and retrospective study were to describe the CPB population isolated in a third-level hospital in Southern Spain between 2015 and 2020 and to establish the relationship between the ST and the epidemiological situation defined by the hospital. CPB were microbiologically studied in all rectal and pharyngeal swabs and clinical samples received between January 2015 and December 2020, characterizing isolates using MicroScan and mass spectrometry. Carbapenemases were detected by PCR and Sanger sequencing, and STs were assigned by multilocus sequence typing (MLST). Isolates were genetically related by pulsed-field gel electrophoresis using Xbal, Spel, or Apal enzymes. The episodes in which each CPB was isolated were recorded and classified as involved or non-involved in an outbreak. There were 320 episodes with CPB during the study period: 18 with K. pneumoniae, 14 with Klebisella oxytoca, 9 with Citrobacter freundii, 11 with Escherichia coli, 46 with Enterobacter cloacae, 70 with Acinetobacter baumannii, and 52 with Pseudomonas aeruginosa. The carbapenemase groups detected were OXA, VIM, KPC, and NDM with various subgroups. Synchronous relationships were notified between episodes of K. pneumoniae and outbreaks for ST15, ST258, ST307, and ST45, but not for the other CPB. There was a major increase in infections with CPB over the years, most notably during 2020, coinciding with the COVID-19 pandemic. This study highlights the usefulness of gene sequencing techniques to control the spread of these microorganisms, especially in healthcare centers. These techniques offer faster results, and a reduction in their cost may make their real-time application more feasible. The combination of epidemiological data with real-time molecular sequencing techniques can provide a major advance in the transmission control of these CPB and in the management of infected patients. Real-time sequencing is essential to increase precision and thereby control outbreaks and target infection prevention measures in a more effective manner.

Rifabutin for infusion (BV100) for the treatment of severe carbapenem-resistant Acinetobacter baumannii infections

Rifamycin antibiotics were discovered during the 1950s, and their main representative, rifampicin, remains a cornerstone treatment for TB. The clinical use of rifamycin is restricted to mycobacteria and Gram-positive infections because of its poor ability to penetrate the Gram-negative outer membrane. Rifabutin, a rifamycin antibiotic approved for the prevention of Mycobacterium avium complex disease, makes an exception to this rule by hijacking the iron uptake system of Acinetobacter baumannii, resulting in potent activity against this important Gram-negative pathogen. Here, we describe recent findings on the specific activity of rifabutin and provide evidence of the need for the development of an intravenous formulation of rifabutin (BV100) for the treatment of difficult-to-treat carbapenem-resistant A.baumannii infections.