Search Results (66)

Leuconostoc spp. are vancomycin-resistant Gram-positive cocci that are used in food production and as pre- and probiotics. However, Leuconostoc spp. can also cause infections. In the present study, the records of patients with Leuconostoc spp. detection between January 2012 and March 2025 were analyzed, inclusive of the underlying risk factors. Leuconostoc spp. was isolated from 32 patients (21 male, 11 females), including nine patients with blood culture evidence. In the majority of patients, Leuconostoc spp. were obtained on the day of admission to the hospital or in the first few days thereafter, arguing against nosocomial acquisition. The median age of men and women (65.3 and 67.8 years) was similar, but seven of the 14 male patients over the age of 65 had the bacteria in blood culture. The female patients with blood culture evidence had suffered from peripartum thrombophlebitis and from anorexia nervosa (BMI 8.8 kg/m²). In contrast, men with Leuconostoc spp. in the blood culture had severe, limiting underlying diseases. While the two women survived, five of the seven blood-culture-positive men died. Overall, our results show that Leuconostoc spp. is mainly acquired in outpatient settings, but men are at a higher risk of acquisition. Colonized men over the age of 60 with severe underlying diseases have a high risk of systemic infection with a fatal outcome. Full article

The war between humans and bacteria started centuries ago. With the advent of antibiotics, there was a temporary ceasefire in this war, but the scenario soon started becoming worse with the emergence of drug-resistant strains within years of the deployment of antibiotics in the market. With the surge in the misuse of antibiotics, there was a drastic increase in the number of multidrug-resistant (MDR) and extensively drug-resistant bacterial strains, even to antibiotics like Methicillin and vancomycin, aggravating the healthcare scenario. The threat of MDR ESKAPE pathogens is particularly high in nosocomial infections, where biofilms formed by bacteria create a protective barrier that makes them highly resistant to antibiotics, complicating the treatment efforts. Scientists are looking at natural and sustainable solutions, as several studies have projected deaths contributed by drug-resistant bacteria to go beyond 50 million by 2050. Many plant-derived metabolites have shown excellent antibacterial and antibiofilm properties that can be tapped for combating superbugs. The present review explores the current status of various studies on antibacterial plant metabolites like alkaloids and flavonoids and their mechanisms in disrupting biofilms and killing bacteria by way of inhibiting key survival strategies of bacteria like motility, quorum-sensing, reactive oxygen species production, and adhesion. These mechanisms were found to be varied in Gram-positive, Gram-negative, and acid-fast bacteria like Mycobacterium tuberculosis, which will be discussed in detail. The successful tapping of the benefits of such plant-derived chemicals in combination with evolving techniques of nanotechnology and targeted drug delivery can go a long way in achieving the goal of One Health, which advocates the unity of multiple practices for the optimal health of people, animals, and the environment. Full article

Background: The global rise of multidrug-resistant Gram-negative bacteria, particularly non-fermenting species and carbapenemase-producing Enterobacteriaceae, poses a significant challenge to hospital infection control. Methods: In this study, a total of 89 Acinetobacter spp. isolates, 14 Pseudomonas aeruginosa, and 14 carbapenem-resistant Enterobacteriaceae isolates were collected from patients in a tertiary hospital. Whole-genome sequencing and antimicrobial susceptibility testing were conducted. Resistance mechanisms and evolutionary relationships were analyzed using phylogenetic analysis and genetic context mapping. Results: Among the non-fermenting isolates, A. baumannii exhibited high resistance to carbapenems, clustering into distinct clonal groups enriched with genes associated with biofilm formation and virulence genes. P. aeruginosa isolates harbored fewer resistance genes but carried notable mutations in the efflux pump systems and the oprD gene. In Enterobacteriaceae, four bla_NDM alleles were identified within a conservative structural sequence, while bla_KPC-2 was located in a non-Tn4401 structure flanked by IS481- and IS1182-like insertion sequences. Phylogenetic analysis revealed that bla_NDM-positive E. coli strains were closely related to susceptible lineages, indicating horizontal gene transfer. Conversely, K. pneumoniae isolates harboring bla_KPC-2 formed a tight clonal cluster, suggesting clonal expansion. Conclusions: The study reveals distinct transmission patterns between resistance genes: horizontal dissemination of bla_NDM and clonal expansion of bla_KPC-2 in K. pneumoniae. These findings emphasize the need for resistance-gene-specific genomic surveillance and infection control strategies to prevent further nosocomial dissemination. Full article

(1) Background: Spontaneous bacterial peritonitis (SBP) is associated with a 20% mortality and is mainly caused by Gram-negative bacteria (GNB); Gram-positive bacteria (GPB) were predominant in some areas; and increased antibiotic resistance was recorded. (2) Methods: A retrospective study was performed between 2018 and 2024. The type of isolated strains, antibiotic susceptibility, and mortality (in-hospital; 30-day; 90-day; and 1-year) were estimated; multivariate analyses evaluated predictive factors for in-hospital mortality risk. (3) Results: 45 culture-positive SBP, 28 culture-negative SBP, 6 bacterascites, and 670 control ascites were diagnosed; GPB represented 60%; two Candida peritonitis and 11 polymicrobial peritonitis (21.6%) were noted (without surgery; peritoneal dialysis; or tegumentary lesion). High resistance rates to cephalosporins and quinolones, and high carbapenem resistance for nosocomial GNB were recorded. A low resistance rate to Tigecycline was noted in all infection types; GPB was susceptible to Linezolid and Vancomycin; and GNB was susceptible to Aztreonam and Colistin. In-hospital mortality was 26.7% (40% for GNB-SBP; 20% for GPB-SBP), similar to culture-negative SBP (21.3%), and higher than in the control group (9%); long-term mortality remained higher. (4) Conclusions: microbial changes to GPB etiology and increasing resistance were noted, but with a lower mortality compared to GNB; higher mortality rates up to 1 year for culture-positive and culture-negative SBP were recorded Full article

Bacteria are the primary microorganisms responsible for nosocomial infections. This study investigates the antibacterial, biofilm-disrupting, and cytotoxic properties of essential oils and their emulsions for the treatment of nosocomial pathogens. The antibacterial activity of selected essential oils and their emulsions was evaluated against clinically relevant strains, including Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa, and Salmonella Enteritidis. Among the tested compounds, cinnamaldehyde exhibited the most potent antibacterial activity, with minimum inhibitory concentrations ranging from 1.31 to 2.62 mg/mL against both Gram-positive and Gram-negative bacteria. Other essential oils, such as cinnamon, eucalyptus, and pine, also demonstrated antibacterial effects, although their efficacy against Pseudomonas aeruginosa was comparatively limited. In biofilm assays, cinnamaldehyde effectively disrupted biofilms formed by S. aureus, methicillin-resistant Staphylococcus aureus, and Pseudomonas aeruginosa, indicating its potential for treating biofilm-associated infections. Cytotoxicity testing revealed that while cinnamon essential oil and cinnamaldehyde exhibited cytotoxic effects at concentrations above 0.1%, other essential oils such as basil and eucalyptus were non-toxic at the tested concentrations. These findings suggest that cinnamaldehyde is a promising agent for managing nosocomial infections, combining effective antibacterial and biofilm-disrupting properties with acceptable safety for non-target cells at appropriate doses. Full article

Background/Objectives: Patients with central nervous system injuries who are hospitalized in intensive care units (ICUs) are at high risk for nosocomial infections. Limited data are available on the incidence and patterns of microbial colonization and infection in this patient population. Methods: To fill this gap, we performed an electronic health record-based study of 1614 chronic patients with brain injury admitted to the ICU from 2017 to 2023. Results: Among the infectious complications, pneumonia was the most common (n = 879; 54.46%). Sepsis was diagnosed in 54 patients, of whom 46 (85%) were diagnosed with pneumonia. The only pathogen that showed an association with the development of pneumonia and sepsis in colonized patients was Pseudomonas aeruginosa (pneumonia: p = 7.2 × 10⁻⁹; sepsis: p = 1.7 × 10⁻⁵). Bacterial isolates from patients with and without pneumonia did not differ in pathogen titer or dynamics, but patients with monomicrobial culture were more likely to develop pneumonia than patients with polymicrobial culture (1 vs. 2 pathogens, p = 0.014; 1 + 2 pathogens vs. 3 + 4 pathogens, p = 2.8 × 10⁻⁶), although the pathogen titer was lower in monoculture than in polyculture. Bacterial isolates from all patients and all culture sites showed high levels of multidrug resistance (Gram-negative bacteria: 88–100%; Gram-positive bacteria: 48–97%), with no differences in multidrug-resistant organism (MDRO) colonization and infection rates. Conclusions: Our results highlight the high burden of MDROs in neurological ICUs and provide novel ecosystem-based insights into mono- and polymicrobial colonization and infection development. These findings may be useful for developing strategies to protect against infections. Full article

The aim of this study was to investigate the differences between nosocomial and community microorganisms isolated from patients with UTI by determining their bacterial profile, antibiotic resistance and ability to produce biofilms. A retrospective study, based on bacterial isolates from consecutive urine samples collected between January 2019 and December 2023, was conducted at a university hospital. The main pathogens isolated from both community and hospital samples were the same, but their frequency of isolation differed. Compared with community-associated cases, hospital-associated infections have more isolates of Acinetobacter baumanii complex. In contrast, Proteus mirabilis isolates were more prevalent in community than in hospital infections. In both hospital and community isolates, gram-positive bacteria showed a lower overall antimicrobial resistance (22%) compared to gram-negative bacteria (30%). The data demonstrated that individual strains exhibited disparate degrees of capacity for biofilm formation. Additionally, the data indicate an inverse correlation between biofilm production and antibiotic resistance. Isolates from community patients exhibited lower capacities for biofilm production in comparison to the capacities demonstrated by microorganisms isolated from nosocomial patients (29% and 35%, respectively). Area-specific surveillance studies can provide valuable information on UTI pathogens and antimicrobial resistance patterns, which can be useful in guiding empirical treatment. Full article

The widespread use of disinfectants and antiseptics has led to the emergence of nosocomial pathogens that are less sensitive to these agents, which in combination with multidrug resistance (MDR) can pose a significant epidemiologic risk. We investigated the susceptibility of nosocomial Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus to a 0.05% chlorhexidine (CHX) solution and a biocidal S7 composite solution based on CHX (0.07%) and benzalkonium chloride (BAC, 0.055%). The prevalence of efflux pump genes associated with biocide resistance and their relationship to antibiotic resistance was also determined. Both biocides were more effective against Gram-positive S. aureus than Gram-negative bacteria. The most resistant strains were P. aeruginosa strains, which were mainly killed by 0.0016% CHX and by 0.0000084% (CHX)/0.0000066% (BAC) S7. The S7 bactericidal effect was observed on P. aeruginosa and S. aureus after 10 min, while the bactericidal effect of CHX was only observed after 30 min. qacEΔ1 and qacE efflux pump genes were prevalent among E. coli and K. pneumoniae, while mexB was more often detected in P. aeruginosa. norA, norB, mepA, mdeA, and sepA were prevalent in S. aureus. The observed prevalence of efflux pump genes highlights the potential problem whereby the sensitivity of bacteria to biocides could decline rapidly in the future. Full article

Enterococcus faecium is a Gram-positive bacterium increasingly identified as a critical nosocomial pathogen that poses significant treatment challenges due to its resistance to multiple antibiotics, particularly vancomycin-resistant E. faecium (VRE) strains. The urgent need for alternative therapeutic strategies has renewed interest in bacteriophage (phage) therapy, given phages specificity and bactericidal potential. This review explores the advancements in phage therapy against antibiotic-resistant E. faecium, including phage morphological diversity, genomic characteristics, and infection mechanisms. The efficacy of phage therapy in in vitro, ex vivo, and in vivo models and the compassionate use in clinical settings are evaluated, highlighting the promising outcomes of phage–antibiotic synergies and biofilm disruption. Key challenges and future research directions are discussed, with a focus on improving therapeutic efficacy and overcoming bacterial resistance. This review emphasizes the potential of phage therapy as a viable solution for managing multidrug-resistant E. faecium infections and underscores the importance of future investigations to enhance clinical applications. Full article

Nosocomial infections, a prevalent issue in intensive care units due to antibiotic overuse, could potentially be addressed by metal oxide nanoparticles (NPs). However, there is still no comprehensive understanding of the impact of NPs’ size on their antibacterial efficacy. Therefore, this study provides a novel investigation into the impact of ZnO NPs’ size on bacterial growth kinetics. NPs were synthesized using a sol–gel process with monoethanolamine (MEA) and water. X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy confirmed their crystallization and size variations. ZnO NPs of 22, 35, and 66 nm were tested against the most common nosocomial bacteria: Escherichia coli, Pseudomonas aeruginosa (Gram-negative), and Staphylococcus aureus (Gram-positive). Evaluation of minimum inhibitory and bactericidal concentrations (MIC and MBC) revealed superior antibacterial activity in small NPs. Bacterial growth kinetics were monitored using optical absorbance, showing a reduced specific growth rate, a prolonged latency period, and an increased inhibition percentage with small NPs, indicating a slowdown in bacterial growth. Pseudomonas aeruginosa showed the lowest sensitivity to ZnO NPs, attributed to its resistance to environmental stress. Moreover, the antibacterial efficacy of paint containing 1 wt% of 22 nm ZnO NPs was evaluated, and showed activity against E. coli and S. aureus. Full article

Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral center in south-eastern Poland. Microbiological analysis of the ascitic fluids was performed in all patients. The presence of microorganisms was found in samples from 17 patients, and 21 pathogens were isolated, including 15 Gram-positive bacteria and 6 Gram-negative bacteria. Staphylococcus epidermidis, MRCNS (methicillin-resistant coagulase-negative staphylococci, resistant to all beta-lactam antibiotics: penicillins, penicillins with beta-lactamase inhibitor, cephalosporins and carbapenems) was the main pathogen detected (19.05%, 4/21), followed by Enterococcus faecalis (9.52%, 2/21), Enterococcus faecium (9.52%, 2/21), Staphylococcus haemolyticus, MRCNS (4.76%, 1/21), Streptococcus mitis (9.52%, 2/21), Streptococcus parasanguinis (9.52%, 2/21), Micrococcus luteus (4.76%, 1/21) and Bacillus spp. (4.76%, 1/21). The following Gram-negative bacteria were also found in the specimens examined: Escherichia coli, ESBL (extended-spectrum β-lactamase producing E. coli) (4.76%, 1/21), Escherichia coli (4.76%, 1/21), Pseudomonas aeruginosa (4.76%, 1/21), Klebsiella oxytoca (9.52%, 2/21) and Sphingomonas paucimobilis (4.76%, 1/21). Gram-positive bacteria caused nosocomial infections in nine patients with SBP, Gram-negative bacteria caused nosocomial infections in two patients. In six patients with SBP, community-acquired infections caused by Gram-negative bacteria were found in three cases, Gram-positive bacteria in two cases, and in one case, community-acquired infection was caused by mixed Gram-positive and Gram-negative. Bacteria isolated from patients with hospital-acquired SBP showed higher drug resistance than those found in patients with non-hospital SBP. Bacterial infections in cirrhotic patients with complications may be responsible for their deteriorating health. Prompt intervention is critical to reducing mortality. Full article

Ventriculitis and nosocomial meningitis caused by carbapenem-resistant Gram-negative and vancomycin-resistant Gram-positive bacteria represent a growing treatment challenge. A case of ventriculitis and bacteremia caused by carbapenem-resistant, KPC-producing Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecium in a young woman with acute leukemia who was successfully treated with meropenem/vaborbactam (MVB), rifampicin, and linezolid is described in this paper. This case report emphasizes the importance of a multidisciplinary strategy, including infectious focus control, for the treatment of device-associated central nervous system (CNS) infections from multidrug-resistant bacteria. Considering the novel resistance patterns, more research on drug penetration into the central nervous system, as well as on the necessity of association therapies, is needed. Full article

The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella Pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) is a group of bacteria very difficult to treat due to their high ability to acquire resistance to antibiotics and are the main cause of nosocomial infections worldwide, posing a threat to global public health. Nosocomial infections with MDR bacteria are found mainly in Intensive Care Units, due to the multitude of maneuvers and invasive medical devices used, the prolonged antibiotic treatments, the serious general condition of these critical patients, and the prolonged duration of hospitalization. Materials and Methods: During a period of one year, from January 2023 to December 2023, this cross-sectional study was conducted on patients diagnosed with sepsis admitted to the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital. Samples taken were tracheal aspirate, catheter tip, pharyngeal exudate, wound secretion, urine culture, blood culture, and peritoneal fluid. Results: The most common bacteria isolated from patients admitted to our Intensive Care Unit was Klebsiella pneumoniae, followed by Acinetobacter baumanii and Pseudomonas aeruginosa. Gram-positive cocci (Enterococcus faecium and Staphilococcus aureus) were rarely isolated. Most of the bacteria isolated were MDR bacteria. Conclusions: The rise of antibiotic and antimicrobial resistance among strains in the nosocomial environment and especially in Intensive Care Units raises serious concerns about limited treatment options. Full article

The infection caused by Clostridioides difficile represents one of the bacterial infections with the greatest increase in incidence among nosocomial infections in recent years. C. difficile is a Gram-positive bacterium able to produce toxins and spores. In some cases, infection results in severe diarrhoea and fulminant colitis, which cause prolonged hospitalisation and can be fatal, with repercussions also in terms of health economics. C. difficile is the most common cause of antibiotic-associated diarrhoea in the healthcare setting. The problem of bacterial forms that are increasingly resistant to common antibiotic treatments is also reflected in C. difficile infection (CDI). One of the causes of CDI is intestinal dysmicrobialism induced by prolonged antibiotic therapy. Moreover, in recent years, the emergence of increasingly virulent strains resistant to antibiotic treatment has made the picture even more complex. Evidence on preventive treatments to avoid recurrence is unclear. Current guidelines indicate the following antibiotics for the treatment of CDI: metronidazole, vancomycin, and fidaxomycin. This short narrative review provides an overview of CDI, antibiotic resistance, and emerging treatments. Full article

Recent research has shown that antibiotic-resistant microorganisms are becoming more prevalent in intensive care units (ICUs) at an exponential rate. Patients in the ICU can get infected by pathogens due to invasive operation procedures and critical health conditions. This study primarily emphasized tracheal samples from ICU patients due to their reliance on ventilators, increasing their susceptibility to Ventilator-Associated Pneumonia (VAP). Moreover, the rise of multidrug-resistant (MDR) pathogens makes treatment strategies more challenging for these patients. In this study, we tested 200 tracheal specimens to determine the prevalence of microorganisms and analyzed the antibiotic susceptibility of these isolates against regular antibiotics, including 4th generation drugs. Among the 273 isolates, 81% were gram-negative bacteria, 10% were gram-positive bacteria, and 9% were fungi. The most prevalent gram-negative bacteria were Acinetobacter spp. (34%), Klebsiella spp. (22%), Pseudomonas spp. (14%), and Escherichia coli (9.2%). The most prevalent gram-positive bacteria were Staphylococcus aureus (5.9%), and the fungi were Candida spp. (7.3%). Among the most prevalent bacteria, except Staphylococcus aureus isolates, around 90% were resistant to multiple drugs, whereas 60% of Acinetobacter spp. and Pseudomonas spp. were extensively drug resistant. Sensitivity analysis against the gram-negative and gram-positive drug panel using a one-way ANOVA test followed by Tukey’s post hoc test showed that in the in vitro assay, colistin was the most effective antibiotic against all gram-negative bacteria. In contrast, linezolid, vancomycin, and fusidic acid were most effective against all gram-positive bacteria. Regular monitoring of nosocomial infections and safe management of highly resistant bacteria can help prevent future pandemics. Full article