Prevalence of Antibiotic Resistance of ESKAPE Pathogens Over Five Years in an Infectious Diseases Hospital from South-East of Romania

Overall status of carbapenem resistance among clinical isolates of Acinetobacter baumannii: a systematic review and meta-analysis

BACKGROUND

Resistance to carbapenems, the first-line treatment for infections caused by Acinetobacter baumannii, is increasing throughout the world. The aim of the present study was to determine the global status of resistance to carbapenems in clinical isolates of this pathogen, worldwide.

METHODS

Electronic databases were searched using the appropriate keywords, including: 'Acinetobacter' 'baumannii', 'Acinetobacter baumannii' and 'A. baumannii', 'resistance', 'antibiotic resistance', 'antibiotic susceptibility', 'antimicrobial resistance', 'antimicrobial susceptibility', 'carbapenem', 'carbapenems', 'imipenem', 'meropenem' and 'doripenem'. Finally, following some exclusions, 177 studies from various countries were included in this study. The data were then subjected to a meta-analysis.

RESULTS

The average resistance rate of A. baumannii to imipenem, meropenem and doripenem was 44.7%, 59.4% and 72.7%, respectively. A high level of heterogeneity (I2 > 50%, P value < 0.05) was detected in the studies representing resistance to imipenem, meropenem and doripenem in A. baumannii isolates. Begg's and Egger's tests did not indicate publication bias (P value > 0.05).

CONCLUSIONS

The findings of the current study indicate that the overall resistance to carbapenems in clinical isolates of A. baumannii is relatively high and prevalent throughout the world. Moreover, time trend analysis showed that the resistance has increased from the year 2000 to 2023. This emphasizes the importance of conducting routine antimicrobial susceptibility testing before selecting a course of treatment, as well as monitoring and controlling antibiotic resistance patterns in A. baumannii strains, and seeking novel treatment options to lessen the emergence and spread of resistant strains and to reduce the treatment failure.

Metal chelation as an antibacterial strategy for Pseudomonas aeruginosa and Acinetobacter baumannii

It is estimated that by 2050, bacterial infections will cause 1.8 million more deaths than cancer annually, and the current lack of antibiotic drug discovery is only exacerbating the crisis. Two pathogens in particular, Gram-negative bacteria A. baumannii and P. aeruginosa, are of grave concern because of their heightened multi-drug resistance due to a dense, impermeable outer membrane. However, targeting specific cellular processes may prove successful in overcoming bacterial resistance. This review will concentrate on a novel approach to combatting pathogenicity by disarming bacteria through the disruption of metal homeostasis to reduce virulence and enhance antibiotic uptake. The varying levels of success in bringing metallophores to clinical trials, with currently only one FDA-approved siderophore antibiotic to date, will also be detailed.

Impact of ESKAPE Pathogens on Bacteremia: A Three-Year Surveillance Study at a Major Hospital in Southern Italy

BACKGROUND/OBJECTIVES

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pose a serious public health threat as they are resistant to multiple antimicrobial agents. Bloodstream infections (BSIs) caused by ESKAPE bacteria have high mortality rates due to the limited availability of effective antimicrobials. This study aimed to evaluate the prevalence and susceptibility of ESKAPE pathogens causing BSIs over three years in a large tertiary hospital in Salerno.

METHODS

Conducted at the Clinical Microbiology Laboratory of San Giovanni di Dio e ''Ruggi D'Aragona'' Hospital from January 2020 to December 2022, blood culture samples from different departments were incubated in the BD BACTEC™ system for 5 days. Species identification was performed using MALDI-TOF MS, and antimicrobial resistance patterns were determined by the VITEK2 system.

RESULTS

Out of 3197 species isolated from positive blood cultures, 38.7% were ESKAPE bacteria. Of these, 59.9% were found in blood culture samples taken from men, and the most affected age group was those aged >60 years. (70.6%). Staphylococcus aureus was the main BSI pathogen (26.3%), followed by Klebsiella pneumoniae (15.8%). Significant resistance rates were found, including 35% of Staphylococcus aureus being resistant to oxacillin and over 90% of Acinetobacter baumannii being resistant to carbapenems.

CONCLUSIONS

These results highlight the urgent need for antimicrobial stewardship programs to prevent incurable infections.

Recombinase-aided amplification assay for rapid detection of imipenem-resistant Pseudomonas aeruginosa and rifampin-resistant Pseudomonas aeruginosa

The indiscriminate use of antibiotics has resulted in a growing resistance to drugs in Pseudomonas aeruginosa. The identification of antibiotic resistance genes holds considerable clinical significance for prompt diagnosis. In this study, we established and optimized a Recombinase-Aided Amplification (RAA) assay to detect two genes associated with drug resistance, oprD and arr, in 101 clinically collected P. aeruginosa isolates. Through screening for the detection or absence of oprD and arr, the results showed that there were 52 Imipenem-resistant P. aeruginosa (IRPA) strains and 23 Rifampin-resistant P. aeruginosa (RRPA) strains. This method demonstrated excellent detection performance even when the sample concentration is 10 copies/μL at isothermal conditions and the results could be obtained within 20 minutes. The detection results were in accordance with the results of conventional PCR and Real-time PCR. The detection outcomes of the arr gene were consistently with the resistance spectrum. However, the antimicrobial susceptibility results revealed that 65 strains were resistant to imipenem, while 49 strains sensitive to imipenem with oprD were identified. This discrepancy could be attributed to genetic mutations. In summary, the RAA has higher sensitivity, shorter time, and lower-cost instrument requirements than traditional detection methods. In addition, to analyze the epidemiological characteristics of the aforementioned drug-resistant strains, we conducted Multilocus Sequence Typing (MLST), virulence gene, and antimicrobial susceptibility testing. MLST analysis showed a strong correlation between the sequence types ST-1639, ST-639, ST-184 and IRPA, while ST-261 was the main subtype of RRPA. It was observed that these drug-resistant strains all possess five or more virulence genes, among which exoS and exoU do not coexist, and they are all multidrug-resistant strains. The non-coexistence of exoU and exoS in P.aeruginosa is related to various factors including bacterial regulatory mechanisms and pathogenic mechanisms. This indicates that the relationship between the presence of virulence genes and the severity of patient infection is worthy of attention. In conclusion, we have developed a rapid and efficient RAA (Recombinase-Aided Amplification) detection method that offers significant advantages in terms of speed, simplicity, and cost-effectiveness (especially in time and equipment aspect). This novel approach is designed to meet the demands of clinical diagnostics.

Global status of antimicrobial resistance in clinical Enterococcus faecalis isolates: systematic review and meta-analysis

BACKGROUND

Due to the increasing emergence of antibiotic resistance in Enterococcus faecalis (E. faecalis), it indicated as potentially opportunistic pathogen causing various healthcare-associated and life-threatening diseases around the world.

OBJECTIVE

The aim of this meta-analysis was to evaluate the weighted pooled resistance rates in clinical E. faecalis isolates based on over time, areas, antimicrobial susceptibility testing (AST), and infection source.

METHODS

We searched the studies in PubMed, Scopus, and Web of Science (November 30, 2022). All statistical analyses were carried out using the statistical package R.

RESULTS

The analysis encompassed a total of 74 studies conducted in 28 countries. According to the meta-regression, the chloramphenicol, fosfomycin, imipenem, linezolid, minocycline, norfloxacin, quinupristin-dalfopristin, and tetracycline resistance rate increased over time. Analysis revealed statistically significant differences in antibiotic resistance rates for ampicillin, chloramphenicol, erythromycin, gentamicin, penicillin, rifampicin, teicoplanin, tetracycline, and vancomycin across various countries.

CONCLUSIONS

Globally, the prevalence of drug resistant E. faecalis strains are on the increase over time. Daptomycin and tigecycline can be an effective agent for the treatment of clinical E. faecalis infections. Considering the low prevalence of antibiotic resistance in continents of Europe and Australia, it is suggested to take advantage of their preventive strategies in order to obtain efficient results in other places with high prevalence of resistance.

Bacterial Resistances and Sensibilities in a Tertiary Care Hospital in Romania-A Retrospective Analysis

The increase in bacterial resistance is currently a global burden for the health care system. In order to evaluate the resistance rates of several bacteria from the most encountered cultures in clinical practice, we performed a retrospective analysis of all of the positive cultures from the year 2021 in a tertiary care hospital in Romania. Our analysis captured 3299 positive cultures. The median age of the patients was 62 years (IQR: 41-71 years old) with a slight predominance among females (53.1%). Overall, the most common cultures were urocultures, wound secretion cultures and blood cultures, and the most common identified bacteria were Escherichia coli, Staphylococcus aureus and Klebsiella spp. Positive cultures with the highest resistance rates were found in the bronchial aspirate cultures, catheter tip cultures, urocultures and blood cultures. Escherichia coli (n = 996) had the highest resistance to ampicillin (19.8%) and trimetoprim-sulfametoxazole (16.4%), while Staphylococcus aureus (n = 698) presented the highest resistance rates to clindamycin (27.4%) and oxaciline (19.7%). Klebsiella (n = 481) presented the highest resistance rates to piperaciline-tazobactam (25.2%) and ampicillin (20.4%), whereas Acinetobacter baumanii (n = 123) presented a resistance rate of more than 50% to carbapenems, gentamicin, ciprofloxacin and ceftazidime. The aim of our study was to identify bacterial resistance rates in order to provide updated clinical data to guide physicians in choosing the best empirical antibiotic treatment, especially in the west part of Romania.

Mechanistic Study of Antimicrobial Effectiveness of Cyclic Amphipathic Peptide [R4W4] against Methicillin-Resistant Staphylococcus aureus Clinical Isolates

Antimicrobial peptides (AMPs) are being explored as a potential strategy to combat antibiotic resistance due to their ability to reduce susceptibility to antibiotics. This study explored whether the [R4W4] peptide mode of action is bacteriostatic or bactericidal using modified two-fold serial dilution and evaluating the synergism between gentamicin and [R4W4] against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) by a checkered board assay. [R4W4] exhibited bactericidal activity against bacterial isolates (MBC/MIC ≤ 4), with a synergistic effect with gentamicin against E. coli (FICI = 0.3) but not against MRSA (FICI = 0.75). Moreover, we investigated the mechanism of action of [R4W4] against MRSA by applying biophysical assays to evaluate zeta potential, cytoplasmic membrane depolarization, and lipoteichoic acid (LTA) binding affinity. [R4W4] at a 16 mg/mL concentration stabilized the zeta potential of MRSA -31 ± 0.88 mV to -8.37 mV. Also, [R4W4] at 2 × MIC and 16 × MIC revealed a membrane perturbation process associated with concentration-dependent effects. Lastly, in the presence of BODIPY-TR-cadaverine (BC) fluorescence dyes, [R4W4] exhibited binding affinity to LTA comparable with melittin, the positive control. In addition, the antibacterial activity of [R4W4] against MRSA remained unchanged in the absence and presence of LTA, with an MIC of 8 µg/mL. Therefore, the [R4W4] mechanism of action is deemed bactericidal, involving interaction with bacterial cell membranes, causing concentration-dependent membrane perturbation. Additionally, after 30 serial passages, there was a modest increment of MRSA strains resistant to [R4W4] and a change in antibacterial effectiveness MIC [R4W4] and vancomycin by 8 and 4 folds with a slight change in Levofloxacin MIC 1 to 2 µg/mL. These data suggest that [R4W4] warrants further consideration as a potential AMP.

Antibacterial Properties and Efficacy of LL-37 Fragment GF-17D3 and Scolopendin A2 Peptides Against Resistant Clinical Strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii In Vitro and In Vivo Model Studies

Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii have emerged as major clinical threats owing to the increasing prevalence of ventilator-associated pneumonia caused by multidrug-resistant or extensively drug-resistant strains. The present study aimed to assess the antibacterial effects and efficacy of LL-37 fragment GF-17D3 and synthetic Scolopendin A2 peptides against resistant clinical strains in vitro and in vivo models. P. aeruginosa, S. aureus, and A. baumannii were isolated from clinical infections. Their antibiotic resistance and minimum inhibitory concentration were assessed. LL-37 fragment GF-17D3 peptide was selected from available databases. Scolopendin A2 peptide's 6th amino acid (proline) was substituted with lysine and peptides and MICs were determined. The biofilm inhibitory activity was quantified at sub MIC concentrations. Synergetic effects of Scolopendin A2 and imipenem were assessed by checkerboard. After mice nasal infection with P. aeruginosa, peptides LD50 was determined. Isolates harbored complete resistance toward the majority of antibiotics and MIC values ranged between 1 and > 512 µg/ml. The majority of isolates exhibited strong biofilm activity. Synthetic peptides showed lower MIC values than antibiotic agents and the lowest MIC values were obtained for synthetic peptides in combination with antibiotics. The Synergisms effect of Scolopendin A2 with imipenem was also determined. Scolopendin A2 was found to have antibacterial efficacy against P. aeruginosa, S. aureus, and A. baumannii with MIC 64 µg/ml, 8 µg/ml, and 16 µg/ml, respectively, and LL37 showed antibacterial efficacy against P. aeruginosa, S. aureus, and A. baumannii with MIC 128 µg/ml, 32 µg/ml, and 32 µg/ml, respectively. Both AMPs decreased biofilms by ≥ 96% at 1 × MIC. The biofilm inhibitory activity was measured at sub MIC concentrations of the peptides and the results demonstrated that Scolopendin A2 exhibited anti-biofilm activity at 1/4 × MIC and 1/2 × MIC concentrations was 47.9 to 63.8%, although LL37 among 1/4 × MIC and 1/2 × MIC concentrations was 21.3 to 49.6% against three pathogens. The combination of Scolopendin A2 and antibiotics demonstrated synergistic activity-resistant strains with FIC values ≤ 0.5 for three pathogens, while LL37 and antibiotics showed synergistic activity FIC values ≤ 0.5 for only P. aeruginosa. Infection model Scolopendin A2 with Imipenem (2 × MIC) was efficacious in vivo, with a 100% survival rate following treatment at 2 × MIC after 120 h. The mRNA expression of biofilm-related genes was decreased for both peptides. Synthesis Scolopendin A2 decreased the expression of biofilm formation genes compared to the control group. Synthetic Scolopendin A2 exhibits antimicrobial activity without causing toxicity on the human epithelial cell line. Based on our findings, it seems that synthetic Scolopendin A2 is an appropriate antimicrobial source. That could be a promising option in combination with antibiotics for a topical medication and in the prevention of acute and chronic infections caused by multidrug-resistant bacteria. Nevertheless, additional experiments are required to assess another potential of this novel AMP.

Antibiotic resistance of ESKAPE group-microorganisms in health institutions from Hermosillo and Ciudad Obregón, Sonora, México

Introduction

Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. are microorganisms referred as the ESKAPE group pathogens. These microorganisms have generated great concern in health institutions around the world since most of them have resistance to multiple antibiotics and cause most infections associated with healthcare, as well as community infections. The aim of this study was the analysis of antibiotic resistance in microorganisms of the ESKAPE group, recovered from clinical samples in 11 health institutions from Hermosillo and Ciudad Obregón in the State of Sonora, México, during the period from 2019 to 2020.

Methods

A cross-sectional, descriptive, observational, and temporality epidemiological study was carried out. A comparative and statistical analysis of antibiotic resistance was carried out using the chi-square test, and small values were analyzed using Fisher's exact test p ≤ 0.05.

Results and discussion

All the ESKAPE group microorganisms showed significant differences in antibiotic resistance percentages between both cities. High resistance percentages for some antibiotics, like cephalosporins and ciprofloxacin were detected for Klebsiella pneumoniae and Acinetobacter baumannii.

Deciphering the structure of a multi-drug resistant Acinetobacter baumannii short-chain dehydrogenase reductase

The rapidly increasing threat of multi-drug-resistant Acinetobacter baumannii infections globally, encompassing a range of clinical manifestations from skin and soft tissue infections to life-threatening conditions like meningitis and pneumonia, underscores an urgent need for novel therapeutic strategies. These infections, prevalent in both hospital and community settings, present a formidable challenge to the healthcare system due to the bacterium's widespread nature and dwindling effective treatment options. Against this backdrop, the exploration of bacterial short-chain dehydrogenase reductases (SDRs) emerges as a promising avenue. These enzymes play pivotal roles in various critical bacterial processes, including fatty acid synthesis, homeostasis, metabolism, and contributing to drug resistance mechanisms. In this study, we present the first examination of the X-ray crystallographic structure of an uncharacterized SDR enzyme from A. baumannii. The tertiary structure of this SDR is distinguished by a central parallel β-sheet, consisting of seven strands, which is flanked by eight α-helices. This configuration exhibits structural parallels with other enzymes in the SDR family, underscoring a conserved architectural theme within this enzyme class. Despite the current ambiguity regarding the enzyme's natural substrate, the importance of many SDR enzymes as targets in anti-bacterial agent design is well-established. Therefore, the detailed structural insights provided in this study open new pathways for the in-silico design of therapeutic agents. By offering a structural blueprint, our findings may provide a platform for future research aimed at developing targeted treatments against this and other multi-drug-resistant infections.

The Role of Stakeholders' Understandings in Emerging Antimicrobial Resistance: A One Health Approach

The increasing misuse of antibiotics in human and veterinary medicine and in agroecosystems and the consequent selective pressure of resistant strains lead to multidrug resistance (AMR), an expanding global phenomenon. Indeed, this phenomenon represents a major public health target with significant clinical implications related to increased morbidity and mortality and prolonged hospital stays. The current presence of microorganisms multi-resistant to antibiotics isolated in patients is a problem because of the additional burden of disease it places on the most fragile patients and the difficulty of finding effective therapies. In recent decades, international organizations like the World Health Organization (WHO) and the European Centre for Disease Prevention and Control (ECDC) have played significant roles in addressing the issue of AMR. The ECDC estimates that in the European Union alone, antibiotic resistance causes 33,000 deaths and approximately 880,000 cases of disability each year. The epidemiological impact of AMR inevitably also has direct economic consequences related not only to the loss of life but also to a reduction in the number of days worked, increased use of healthcare resources for diagnostic procedures and the use of second-line antibiotics when available. In 2015, the WHO, recognising AMR as a complex problem that can only be addressed by coordinated multi-sectoral interventions, promoted the One Health approach that considers human, animal, and environmental health in an integrated manner. In this review, the authors try to address why a collaboration of all stakeholders involved in AMR growth and management is necessary in order to achieve optimal health for people, animals, plants, and the environment, highlighting that AMR is a growing threat to human and animal health, food safety and security, economic prosperity, and ecosystems worldwide.

Inhibition of Acinetobacter baumannii Biofilm Formation Using Different Treatments of Silica Nanoparticles

There exists a multitude of pathogens that pose a threat to human and public healthcare, collectively referred to as ESKAPE pathogens. These pathogens are capable of producing biofilm, which proves to be quite resistant to elimination. Strains of A. baumannii, identified by the "A" in the acronym ESKAPE, exhibit significant resistance to amoxicillin in vivo due to their ability to form biofilm. This study aims to inhibit bacterial biofilm formation, evaluate novel silica nanoparticles' effectiveness in inhibiting biofilm, and compare their effectiveness. Amoxicillin was utilized as a positive control, with a concentration exceeding twice that when combined with silica NPs. Treatments included pure silica NPs, silica NPs modified with copper oxide (CuO.SiO2), sodium hydroxide (NaOH.SiO2), and phosphoric acid (H3PO4.SiO2). The characterization of NPs was conducted using scanning electron microscopy (SEM), while safety testing against normal fibroblast cells was employed by MTT assay. The microtiter plate biofilm formation assay was utilized to construct biofilm, with evaluations conducted using three broth media types: brain heart infusion (BHI) with 2% glucose and 2% sucrose, Loria broth (LB) with and without glucose and sucrose, and Dulbecco's modified eagle medium/nutrient (DMEN/M). Concentrations ranging from 1.0 mg/mL to 0.06 µg/mL were tested using a microdilution assay. Results from SEM showed that pure silica NPs were mesoporous, but in the amorphous shape of the CuO and NaOH treatments, these pores were disrupted, while H3PO4 was composed of sheets. Silica NPs were able to target Acinetobacter biofilms without harming normal cells, with viability rates ranging from 61-73%. The best biofilm formation was achieved using a BHI medium with sugar supplementation, with an absorbance value of 0.35. Biofilms treated with 5.0 mg/mL of amoxicillin as a positive control alongside 1.0 mg/mL of each of the four silica treatments in isolation, resulting in the inhibition of absorbance values of 0.04, 0.13, 0.07, 0.09, and 0.08, for SiO2, CuO.SiO2, NaOH.SiO2 and H3PO4.SiO2, respectively. When amoxicillin was combined, inhibition increased from 0.3 to 0.04; NaOH with amoxicillin resulted in the lowest minimum biofilm inhibitory concentration (MBIC), 0.25 µg/mL, compared to all treatments and amoxicillin, whereas pure silica and composite had the highest MBIC, even when combined with amoxicillin, compared to all treatments, but performed better than that of the amoxicillin alone which gave the MBIC at 625 µg/mL. The absorbance values of MBIC of each treatment showed no significant differences in relation to amoxicillin absorbance value and relation to each other. Our study showed that smaller amoxicillin doses combined with the novel silica nanoparticles may reduce toxic side effects and inhibit biofilm formation, making them viable alternatives to high-concentration dosages. Further investigation is needed to evaluate in vivo activity.

Temporo-spatial variations in resistance determinants and clonality of Acinetobacter baumannii and Pseudomonas aeruginosa strains from Romanian hospitals and wastewaters

Background

Romania is one of the European countries reporting very high antimicrobial resistance (AMR) rates and consumption of antimicrobials. We aimed to characterize the AMR profiles and clonality of 304 multi-drug resistant (MDR) Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) strains isolated during two consecutive years (2018 and 2019) from hospital settings, hospital collecting sewage tanks and the receiving wastewater treatment plants (WWTPs) located in the main geographical regions of Romania.

Methods

The strains were isolated on chromogenic media and identified by MALDI-TOF-MS. Antibiotic susceptibility testing and confirmation of ESBL- and CP- producing phenotypes and genotypes were performed. The genetic characterization also included horizontal gene transfer experiments, whole-genome sequencing (WGS), assembling, annotation and characterization.

Results

Both clinical and aquatic isolates exhibited high MDR rates, especially the Ab strains isolated from nosocomial infections and hospital effluents. The phenotypic resistance profiles and MDR rates have largely varied by sampling point and geographic location. The highest MDR rates in the aquatic isolates were recorded in Galați WWTP, followed by Bucharest. The Ab strains harbored mostly bla_OXA-23, bla_OXA-24, bla_SHV, bla_TEM and bla_GES, while Pa strains bla_IMP, bla_VIM, bla_NDM, bla_VEB, bla_GES and bla_TEM, with high variations depending on the geographical zone and the sampling point. The WGS analysis revealed the presence of antibiotic resistance genes (ARGs) to other antibiotic classes, such as aminoglycosides, tetracyclines, sulphonamides, fosfomycin, phenicols, trimethoprim-sulfamethoxazole as well as class 1 integrons. The molecular analyses highlighted: (i) The presence of epidemic clones such as ST2 for Ab and ST233 and ST357 for Pa; (ii) The relatedness between clinical and hospital wastewater strains and (iii) The possible dissemination of clinical Ab belonging to ST2 (also proved in the conjugation assays for bla_OXA-23 or bla_OXA-72 genes), ST79 and ST492 and of Pa strains belonging to ST357, ST640 and ST621 in the wastewaters.

Conclusion

Our study reveals the presence of CP-producing Ab and Pa in all sampling points and the clonal dissemination of clinical Ab ST2 strains in the wastewaters. The prevalent clones were correlated with the presence of class 1 integrons, suggesting that these isolates could be a significant reservoir of ARGs, being able to persist in the environment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01156-1.

Clonal Dissemination of Extended-Spectrum Cephalosporin-Resistant Enterobacterales between Dogs and Humans in Households and Animal Shelters of Romania

Faecal carriage of extended-spectrum cephalosporin-resistant (ESC-R) Enterobacterales in healthy pets is a concerning issue. This study aimed to determine the prevalence, genetic background, and potential for interspecies transmission of these bacteria between dogs and humans within the same household (HH) or shelter environment in Romania. Faecal samples (n = 263) collected from healthy dogs (n = 102), their owners (n = 32), as well as dogs (n = 110) and staff (n = 19) from dog shelters, were screened for ESC-R carriage. Clonal relatedness of canine and human Escherichia coli isolates was established using Fourier Transform Infrared Spectroscopy (FTIR), followed by Illumina WGS of selected isolates. The highest prevalence of ESC-R Enterobacterales faecal carriage was identified in staff working at dog shelters (78.9%), followed by dogs from households (44.11%), dog owners (43.7%), and dogs from shelters (27%). FTIR identified 15 clusters of closely related E. coli isolates, including dog and human isolates from the same environment. Co-carriage of ESC-R isolates in both the dog and owner was identified in 12 HHs (37.5%), with two HHs (6%) having both the owner and dog carrying isolates with identical FTIR spectra, phylogroup, resistance genes, and Inc plasmids. Major ExPEC lineages such as ST127, ST10, ST155, and ST88 were detected in human and dog isolates. Our study revealed a high prevalence of faecal ESC-R E. coli carriage in both dogs and humans from Romanian households and shelters, where bidirectional clonal transmission between humans and dogs is likely. Furthermore, we identified ESC-R Enterobacterales co-carriage in people and dogs sharing the same environment using FTIR, demonstrating its value in AMR surveillance for humans and animals.

Molecular Typing Reveals Environmental Dispersion of Antibiotic-Resistant Enterococci under Anthropogenic Pressure

As a consequence of global demographic challenges, both the artificial and the natural environment are increasingly impacted by contaminants of emerging concern, such as bacterial pathogens and their antibiotic resistance genes (ARGs). The aim of this study was to determine the extent to which anthropogenic contamination contributes to the spread of antibiotic resistant enterococci in aquatic compartments and to explore genetic relationships among Enterococcus strains. Antimicrobial susceptibility testing (ampicillin, imipenem, norfloxacin, gentamycin, vancomycin, erythromycin, tetracycline, trimethoprim-sulfamethoxazole) of 574 isolates showed different rates of phenotypic resistance in bacteria from wastewaters (91.9–94.4%), hospital effluents (73.9%), surface waters (8.2–55.3%) and groundwater (35.1–59.1%). The level of multidrug resistance reached 44.6% in enterococci from hospital effluents. In all samples, except for hospital sewage, the predominant species were E. faecium and E. faecalis. In addition, E. avium, E. durans, E. gallinarum, E. aquimarinus and E. casseliflavus were identified. Enterococcus faecium strains carried the greatest variety of ARGs (bla_TEM-1, aac(6′)-Ie-aph(2″), aac(6′)-Im, vanA, vanB, ermB, mefA, tetB, tetC, tetL, tetM, sul1), while E. avium displayed the highest ARG frequency. Molecular typing using the ERIC2 primer revealed substantial genetic heterogeneity, but also clusters of enterococci from different aquatic compartments. Enterococcal migration under anthropogenic pressure leads to the dispersion of clinically relevant strains into the natural environment and water resources. In conclusion, ERIC-PCR fingerprinting in conjunction with ARG profiling is a useful tool for the molecular typing of clinical and environmental Enterococcus species. These results underline the need of safeguarding water quality as a strategy to limit the expansion and progression of the impending antibiotic-resistance crisis.

From the Intersection of Food-Borne Zoonoses and EU Green Policies to an In-Embryo One Health Financial Model

The European Union (EU) adopts the One Health (OH) approach, based on the relationships between human, animal, and environmental health. OH concerns a multitude of aspects, some of which are discussed here. OH overlaps the European Green Deal plan and its relaunched Farm to Fork Strategy, which aims at spreading organic farms adopting the circular economy, in order to improve human health through both better environmental conditions and healthier food. Nevertheless, zoonoses cause sanitary cost in terms of infected farm personnel, lower productivity, and lower fertility of infected farm animals. In such scenarios, the decreased breeding yield and the lower income induce higher cost of farm products, meaning that the market price rises, becoming uncompetitive when compared to the prices of industrial products. Consequently, lower revenues can hinder the farm growth expected in the framework of the EU Green Deal. Since zoonosis control is a key element in aligning EU policies aimed at achieving the EU Green Deal goal of "ZERO environmental impact" by 2050, the authors suggest the inclusion of the parameter economic health in the OH approach, in order to individuate EU Member States (MSs) economically unable to conduct eradication programmes and to finance them. Economic health is here considered as a starting point of the new ethical and science-based One Health Financial Model that the authors suggest as an in-embryo model, in which specific rules should regulate public funds, private investments, and trading, which should exclusively concern public services and private enterprises complying with most of the OH parameters. In this way, economic losses due to collateral negative effects deriving from human activities can be progressively decreased, and the entire planet will benefit from the process. Despite the considerable efforts being carried out in the context of the OH approach, war causes tragic and devastating effects on the physical and mental health of human beings, on their lives, on pandemic and zoonotic threats, on animals, on plants and, last but not least, on the environment. War is incompatible with OH. Enormous efforts for peace are therefore urgently needed.

Design, Synthesis and Mechanistic Studies of Novel Isatin-Pyrazole Hydrazone Conjugates as Selective and Potent Bacterial MetAP Inhibitors

Methionine aminopeptidases (MetAPs) are attractive drug targets due to their essential role in eukaryotes as well as prokaryotic cells. In this study, biochemical assays were performed on newly synthesized Isatin-pyrazole hydrazones (PS1-14) to identify potent and selective bacterial MetAPs inhibitors. Compound PS9 inhibited prokaryotic MetAPs, i.e., MtMetAP1c, EfMetAP1a and SpMetAP1a with Ki values of 0.31, 6.93 and 0.37 µM, respectively. Interestingly, PS9 inhibited the human analogue HsMetAP1b with Ki (631.7 µM) about ten thousand-fold higher than the bacterial MetAPs. The in vitro screening against Gram-positive (Enterococcus faecalis, Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumonia and Escherichia coli) bacterial strains also exhibited their antibacterial potential supported by minimum bactericidal concentration (MBC), disk diffusion assay, growth curve and time-kill curve experiments. Additionally, PS6 and PS9 had synergistic effects when combined with ampicillin (AMP) and ciprofloxacin (CIP) against selective bacterial strains. PS9 showed no significant cytotoxic effect on human RBCs, HEK293 cells and Galleria mellonella larvae in vivo. PS9 inhibited the growth of multidrug-resistant environmental isolates as it showed the MIC lower than the standard drugs used against selective bacterial strains. Overall, the study suggested PS9 could be a useful candidate for the development of antibacterial alternatives.

Five-Year Survey of Asymptomatic Colonization with Multidrug-Resistant Organisms in a Romanian Tertiary Care Hospital

Purpose

To determine the rate of carriage of multidrug-resistant organisms (MDROs) between 2015 and 2019 among patients admitted to the National Institute of Infectious Diseases “Prof. Dr. Matei Balș,” from Bucharest, Romania.

Methods

Nasal, throat, and rectal/perirectal screening swabs were collected either immediately or during the first 24 hours of admission and sent to the microbiology laboratory where the following MDROs were identified: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, carbapenem-resistant/carbapenemase-producing Enterobacterales (CRE/CPE), multidrug-resistant/extended drug-resistant Acinetobacter baumannii (MDR/XDR-AB), and multidrug-resistant/extended drug-resistant Pseudomonas aeruginosa (MDR/XDR-PA).

Results

A total of 5083 unique patients were screened for MRSA and 5008 for VRE, ESBL/CRE/CPE, MDR/XDR-AB, and MDR/XDR-PA. MRSA was detected in 8.24% of patients, VRE in 17.67%, ESBL Enterobacterales in 25.85%, and CPE in 6.13%. MDR/XDR-AB was found in 1.59% and MDR/XDR-PA in 1.91% of patients. The rates of carriage increased between 2015 and 2019 for MRSA (7.23–7.6%), VRE (9–16.68%), CPE (1.15–6.77%), MDR/XDR-PA (1.15–1.91%), and MDR/XDR-AB (1.15–2.04%). OXA-48-type carbapenemase was predominant in Klebsiella pneumoniae (68.62%) and Escherichia coli (89.47%). CPE bacteria other than Klebsiella pneumoniae and Escherichia coli identified in our study carried mostly metallo-beta-lactamase (n = 28, 84.85%).

Conclusion

In this study, 37% of the unique patients screened over five years were found to be MDRO carriers. The proportion of VRE and CPE rectal carriers increased significantly between 2015 and 2019. The most frequently isolated carbapenemase was the OXA-48 type.

An Overview of Healthcare Associated Infections and Their Detection Methods Caused by Pathogen Bacteria in Romania and Europe

Healthcare-associated infections can occur in different care units and can affect both patients and healthcare professionals. Bacteria represent the most common cause of nosocomial infections and, due to the excessive and irrational use of antibiotics, resistant organisms have appeared. The most important healthcare-associated infections are central line-associated bloodstream infections, catheter-associated urinary tract infections, surgical site, soft tissue infections, ventilator-associated pneumonia, hospital acquired pneumonia, and Clostridioides difficile colitis. In Europe, some hospitalized patients develop nosocomial infections that lead to increased costs and prolonged hospitalizations. Healthcare-associated infection prevalence in developed countries is lower than in low-income and middle-income countries such as Romania, an Eastern European country, where several factors contribute to the occurrence of many nosocomial infections, but official data show a low reporting rate. For the rapid identification of bacteria that can cause these infections, fast, sensitive, and specific methods are needed, and they should be cost-effective. Therefore, this review focuses on the current situation regarding healthcare-associated infections in Europe and Romania, with discussions regarding the causes and possible solutions. As a possible weapon in the fight against the healthcare-associated infections, the diagnosis methods and tests used to determine the bacteria involved in healthcare-associated infections are evaluated.

Descriptive Analysis of Circulating Antimicrobial Resistance Genes in Vancomycin-Resistant Enterococcus (VRE) during the COVID-19 Pandemic

COVID-19 offers ideal premises for bacteria to develop antimicrobial resistance. In this study, we evaluated the presence of several antimicrobial resistance genes (ARG) in vancomycin-resistant Enterococcus (VRE) isolated from rectal swabs from patients at a hospital in Cluj-Napoca, Romania. Rectal swabs were cultivated on CHROMID^® VRE (bioMérieux, Marcy—l’ Étoile, France) and positive isolates were identified using MALDI-TOF Mass Spectrometry (Bruker Daltonics, Bremen, Germany) and further analyzed using the PCR technique for the presence of the following ARGs: van A, van B, tet(M), tet(L), ermB, msrA, mefA, aac(6′)-Im, aph(2)-Ib, ant(4′)-Ia, sul1, sul2, sul3, and NDM1. We isolated and identified 68 isolates of Enterococcus faecium and 11 isolates of Enterococcus faecalis. The molecular analysis showed 66 isolates positive for the vanA gene and eight positive for vanB. The most frequent association of ARG in VRE was vanA-tet(M)-ermB. There was no statistically significant difference between Enterococcus faecium and Enterococcus faecalis regarding ARGs. Our work proves that during the COVID-19 pandemic, highly resistant isolates of Enterococcus were present in patients in the intensive care unit; thus, better healthcare policies should be implemented for the management and control of these highly resistant isolates in the future.

Antibacterial Activity of Cerium Oxide Nanoparticles against ESKAPE Pathogens

We studied the antimicrobial characteristics of cerium oxide (CeO2) nanoparticles synthesized by hydrothermal technique. The versatile characterization techniques were employed to study the CeO2 nanoparticle structural and optical properties. These techniques included field emission scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. The X-ray diffraction and Raman studies validated the cubic structure of the synthesized CeO2 nanoparticles with average diameters ~3–5 nm. The antibacterial activities and minimal inhibition concentrations (MICs) of CeO2 nanoparticles were tested against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.). Our data revealed that CeO2 nanoparticles at a concentration of 50 µg/mL generated a maximum inhibition zone against all tested pathogens. However, S. aureus, P. aeruginosa, and K. pneumoniae exhibited the higher sensitivity, while E. cloacae, E. faecium, and A. baumannii were the least sensitive to CeO2 nanoparticles. In conclusion, our results demonstrate that CeO2 nanoparticles possess an effective antibacterial activity against ESKAPE pathogens and may be used as a potential bionanomaterial for in vivo therapeutic applications.