Gram-negative Microorganisms Research Articles

Sepsis in elderly patients: investigation of prognostic factors in a secondary healthcare facility

AimTo evaluate risk factors affecting the prognosis of sepsis in elderly patients.MethodThe study was conducted retrospectively in a secondary healthcare institution between 2016 and 2023. Elderly patients (> 65 years) admitted with sepsis were included. Demographic data, laboratory parameters on the day of diagnosis, sepsis origin, causative microorganisms, and mortality on the 28th day were recorded.ResultsA total of 179 elderly patients were included. The median age was 82 and 44% were male. The mortality rate was 49% on the 28th day. Hypertension was more common in the non-survived patients. Blood urea nitrogen (OR 1.03 (1.00-1.05) p = 0.007), and albumin (OR 0.26 (0.10–0.62) p = 0.003), levels were a predictor of mortality at the time of the admission. In the non-survived patients, Systemic inflammatory response syndrome (SIRS) and quick sepsis-related organ failure assessment scores were higher at the time of sepsis diagnosis (p < 0.001). The rate of septic shock (79.5% vs. 33%), intensive care unit (99% vs. 90%), mechanical ventilation (87.5% vs. 55%), and vasopressor needs (55% vs. 27.5%) were significantly higher in the non-survived patients. The rate of bacteremia was found to be higher in the non-survived patient group (26%) than in the survivors (13.2%). The rate of Gram-negative microorganisms was significantly higher in the non-survived patient group than in the survivors (63% vs. 27%; p < 0.001). The most frequently isolated bacteria were Klebsiella pneumoniae (33%) in blood culture; it was Escherichia coli (35%) in urine cultures and Acinetobacter baumanii (40%) in sputum cultures. On the 3-5th day of treatment, the clinical response rate was lower in the non-survived patient group (29%) than in the surviving’s (53%) (p = 0.001). The most important determinants for the mortality were hypertension (OR 2.39 (1.25–4.95) p = 0.019), SIRS score (OR 1.86 (1.32–2.61) p < 0.001) and Gram-negative bacteria sepsis (OR 2.53 (1.22–5.22), p = 0.012).ConclusionThe number and the proportion of the elderly population is increasing worldwide, and sepsis is one of the most common causes of death in elderly patients. Knowing the poor prognostic factors is important for early treatment and to reduce mortality.

Bacterial infections in pediatric oncology patients- a single center experience

Patients with neoplasms have a high predisposition to bacterial infections, due to the implemented treatment that impairs immunity and numerous risk factors. Numerous research studies have been published on this problem but epidemiological studies are insufficient, and existing data are difficult to generalize on different populations. The aim of the study was to assess the epidemiology of bacterial and fungal bloodstream infections and contaminations in cancer patients hospitalized between 2011 and 2021, with a focus on identifying predominant pathogens, resistance mechanisms, and evaluating the effectiveness of infection prophylaxis. We collected data of blood contaminations and infections epidemiology with cooperation with the Department of Clinical Microbiology UCH. Between 2011 and 2021, 7,667 blood samples were collected and 32,610 tests were performed on 1,914 patients. The analysed cultures were divided into 3 groups depending on the substrate specific for a given group of microorganisms. The number positive test result was 5.5%. The highest detection was noticed in 2021. Differences in the distribution of patients with positive and negative results in individual years were not statistically significant. The most common pathogen detected was Staphylococcus epidermidis, which was also the leader among Gram-positive microorganisms. There were not dominant species among the isolated Gram-negative microorganisms. Detection of anaerobic organisms was rare (only 4 different anaerobic organisms were isolated in single patients). The same was among the fungal observed. Mechanisms of resistance were included in the analysis of all identified strains- the most common was methicillin-resistant Staphylococcus epidermidis (MRSE). Our results confirmed that bacterial infections are still a problem and may indicate the effectiveness of prophylaxis. Most of our results are consistent with the current literature, however we were able to highlight data unique to our patient population. Our findings can be helpful for clinical practice and be base for further research.

Сombat wounds microflora in modern warfare

The purpose. Analysis of the clonal characteristics and antibiotic resistance of the most prevalent wound pathogens among individuals injured in the Russian-Ukrainian war to support microbiota surveillance of combat wounds and optimize treatment strategies. Materials and Methods. A bacteriological examination was conducted on wound specimens from 171 injured individuals who received treatment in three healthcare facilities located in the central region of Ukraine between 2022 and 2023. Results from bacteriological studies of 151 wounded individuals treated in the same hospitals during the period from 2017 to 2020 were used for comparative analysis. Antibiotic susceptibility testing was performed using the disk diffusion method in accordance with the recommendations of EUCAST (European Committee on Antimicrobial Susceptibility Testing). To determine antibiotic resistance determinants and phylogenetic relationships between strains, whole-genome sequencing (WGS) of the isolated cultures was carried out using next-generation sequencing (NGS) technology on the Applied Biosystems/Life Technologies SOLiD platform, followed by core genome multilocus sequence typing (cgMLST). Identification of resistance genes was conducted by comparing the obtained nucleotide sequences against the GenBank® database of the National Center for Biotechnology Information (NCBI) using the BLAST (Basic Local Alignment Search Tool) algorithm. Data analysis was performed using descriptive statistics with assessment of statistical significance of differences between alternative indicators (case proportions) by Student’s t-test, utilizing the STATISTICA 13.3 software package (license AXA905I924220FAACD‐N). Results. The composition of predominant wound pathogens in the most recent observation period changed insignificantly compared to the 2017–2020 period. Throughout the entire observation period, the dominant species among wound infection pathogens were A. baumannii, P. aeruginosa, and K. pneumoniae. Among the isolated strains, a high frequency of high-risk global clonal lineages was observed, namely K. pneumoniae ST395, ST147; A. baumannii ST2, ST78; P. aeruginosa ST773 and ST1047. Over 90% of isolates, regardless of species, were multidrug-resistant. A high prevalence of genes responsible for the production of beta-lactamases (blaOXA-23, blaOXA-72) and metallo-beta-lactamases (blaNDM-1, blaIMP-1) was identified among the isolated strains. Conclusion. A bacteriological study of combat wound content was conducted among injured individuals receiving treatment at three healthcare institutions located in the central region of Ukraine during the periods of 2017–2020 and 2022–2023. The results indicate a shift in the etiological structure of purulent-inflammatory complications of combat wounds, with a predominance of Gram-negative microorganisms, primarily non-fermenting bacteria and members of the Enterobacteriaceae family. It was found that, following the onset of the full-scale invasion, the total proportion of these microorganisms among all isolated strains significantly increased to 93.5%, compared to 80.2% prior to 2021 (p&lt;0.001). Notably, the frequency of Enterobacteriaceae isolation from wounds showed an upward trend: Escherichia coli was isolated in 9.1% of cases versus 5.0% before 2021, while the proportion of Klebsiella pneumoniae significantly increased to 20.7% compared to 8.6% prior to the full-scale war (p&lt;0.001). High-risk globally distributed clonal lineages, such as K. pneumoniae ST395 and ST147; A. baumannii ST2 and ST78; and P. aeruginosa ST773 and ST1047 were the most frequently identified among the isolates. More than 90% of all isolates, regardless of species, were multidrug-resistant. Molecular genetic analysis revealed a high prevalence of international clones of A. baumannii associated with increased antibiotic resistance. Specifically, 17.6% of A. baumannii isolates belonged to the high-risk, globally distributed ST2 lineage (IC II), which harbored genes encoding carbapenemases blaOXA-23 and blaOXA-72, as well as 16S rRNA methyltransferase (armA), conferring resistance to aminoglycosides and fluoroquinolones. Furthermore, 33.8% of isolates were identified as belonging to another high-risk international clone, IC VI (ST78, ST1077). The high concentration of injured individuals in both domestic and foreign healthcare facilities created a vast reservoir of multidrug-resistant microorganisms with a significant potential for global dissemination. This situation necessitates close surveillance and continuous microbiological monitoring, as well as the development and implementation of a comprehensive set of multimodal infection prevention and control measures.

Etiological Structure of Lower Respiratory Tract Pathogens in Treatment and Rehabilitation of Patients with Chronic Critical Illness in Intensive Care Units

BACKGROUND: Chronic critical illness is characterized by ventilator dependence, systemic inflammatory response, multiorgan failure, secondary sarcopenia, hypermetabolism and hypercatabolism, and protein–energy malnutrition. In this category of intensive care unit patients, lower respiratory tract infections remain a significant cause of adverse outcomes, prolonged hospital stays, and increased treatment costs. It is impossible to provide adequate empirical treatment of lower respiratory tract infections without knowing the etiology and resistance of the leading pathogens of this nosocomial infection in a specific department of a healthcare organization. AIM: The study aimed to characterize the etiology of lower respiratory tract infections in intensive care unit patients from 2020 to 2023, determine their antibiotic susceptibility, identify the most common resistance mechanisms of leading pathogens, and provide recommendations for optimizing antimicrobial therapy. METHODS: The study included patients with confirmed lower respiratory tract infections, primarily those with prolonged or chronic critical illnesses, from 2020 to 2023. The BD Phoenix 100 automated analyzer was used to identify the pathogens. Susceptibility was interpreted using EUCAST criteria. RESULTS: From 2020 to 2023, the top 10 pathogens responsible for lower respiratory tract infections in 1,007 patients were predominantly gram-negative microorganisms. For this period, the following trends were noted: an increase in Acinetobacter baumannii from 13.22% to 21.40% (p 0.001), and a decrease in Escherichia coli from 7.90% to 2.98% (p 0.001). From 2020 to 2023, the resistance of Klebsiella pneumoniae and Acinetobacter baumannii to carbapenems increased significantly, from 80.50% to 91.64% (p 0.001) and from 89.89% to 98.14% (p 0.001), respectively. Among carbapenemase-producing Klebsiella pneumoniae, resistance to colistin, tigecycline, and ceftazidime + avibactam increased from 4.95% to 9.00% (p 0.001), from 48.76% to 71.28% (p 0.001), and from 33.06% to 47.73% (p = 0.041), respectively. CONCLUSION: The predominant pathogens causing lower respiratory tract infections in intensive care unit patients included Gram-negative bacteria with a high level of antibiotic resistance. These bacteria included carbapenem-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The etiological structure of lower respiratory tract infections and their antibiotic susceptibility in these patients should be evaluated to create local protocols for effective empirical antimicrobial therapy in each specific intensive care unit of a healthcare organization.

Characteristics of ventilator-associated pneumonia due to Gram-negative bacteria in the intensive care unit: A single-center experience.

Ventilator-associated pneumonia (VAP) is one of the most common and serious infections in hospitalized patients. VAP is associated with worse outcomes and significant morbidity and mortality worldwide. Our primary goal in this study was to identify the VAP pathogen with its distribution characteristics, clarify risk factors, prognosis, and outcomes, and help reduce associated morbidity and mortality. This retrospective observational study was conducted between June 2019 and June 2022 in 3 general intensive care units of a training and research hospital. Data on demographic, clinical and laboratory parameters were collected retrospectively from medical cards and electronic records. A total of 204 patients were diagnosed with VAP caused by Gram-negative microorganisms. Chronic renal failure (RF) and neurological diseases were significantly associated with mortality (P = .01, P = .023). The duration of mechanical ventilation before VAP and the duration of mechanical ventilation were significantly longer in survivors compared to non-survivors. The number of patients with early VAP was significantly higher, and the days of VAP were shorter in the non-survivors compared to the survivors (P = .006, P = .016). The number of VAP episodes (P = .0001), the presence of RF, acute respiratory distress syndrome, bacteremia, and sepsis before VAP (<48 hours) were associated with mortality. Intensive care unit and the length of hospital stay were significantly shorter in non-survivors than in survivors (P = .0003, P = .0001). Administration of monotherapy, inadequate empirical antibiotic therapy, inadequate antibiotic therapy (P = .004, P = .002, and P = .0006), persistence of the pathogen (P = .0001), C-reactive protein and procalcitonin levels (P = .002, P = .041) were associated with mortality. The presence of neurological diseases and RF was associated with a greater likelihood of mortality in patients with VAP. As risk factors, early-onset VAP, presence of RF-acute respiratory distress syndrome-bacteremia-sepsis 48 hours before VAP, organ failure, need for hemodialysis, shock and the persistence of the pathogen increased the risk of mortality.

Unveiling the Biotechnological Potential of Cyanobacteria from the Portuguese LEGE-CC Collection Through Lipidomics and Antioxidant and Lipid-Lowering Properties

Cyanobacteria are gram-negative prokaryotic microorganisms composed of both broad morphological and phylogenetic diversity inherited from diverse ecosystems like aquatic, terrestrial, or extremophilic environments. In this study, three cyanobacteria strains from the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE-CC) were obtained from different environments in Portugal. Polyphasic analysis was applied for taxonomic identification. The proximate composition analysis indicated the lipid content (6.2% to 9.1% dry weight (DW)), protein content (28.2% to 62.9% DW), and carbohydrate content (19.5% to 46.1% DW). The fatty acid (FA) profiles of the strains revealed the presence of 19 different FAs, with FA 16:0 found in the highest abundance. The lipidomic analysis revealed 230 lipid species, with Laspinema sp. LEGE 06078 displaying the highest diversity (125 lipid species). These included species-specific and common lipids species that denote biochemical uniqueness that are also carriers of omega-3 FA (n−3). Biological assays exhibited strong antioxidant activity against ABTS•+ and DPPH• in Laspinema sp. LEGE 06078, while Sphaerospermopsis sp. LEGE 00249 was renowned for reducing lipids in zebrafish larvae. The findings are of immense significance on the lipidomics diversity of cyanobacteria in terms of nutrition, health, and biotechnology, such as addressing obesity and sustainable resource production.

Evaluation of Gram-negative hospital-acquired infections and antibiotic resistance in the pediatric intensive care unit.

We retrospectively analyzed the frequency of healthcare-associated infections (HAIs), infection sites, Gram-negative microorganisms in the cultures, and antibiotic resistance patterns; recorded in the pediatric intensive care unit (PICU); between 2017 and 2023; based on the records in our hospital's infection control surveillance system. Our aim was to determine the state of infections over the years and the status of antibiotic resistance. Medical records of PICU patients, between 1 January 2017 and 31 July 2023, whose cultures were identified to have Gram-negative bacterial growth, were evaluated retrospectively. A total of 125 nosocomial infections were recorded. Pseudomonas aeruginosa and Klebsiella pneumoniae were the most frequently identified and had equal growth rates in blood culture. K. pneumoniae were most frequently identified in the central venous catheter (CVC). Mortality was significantly higher for patients with fungal growth, congenital diseases, and males (p < 0.05); except in patients with CVC. Patients with congenital diseases had a shorter median survival time (65 days) compared to chronic disease patients (151 days; p < 0.005). Cox regression analysis indicated that comorbidity was a significant risk factor for survival time. The risk of mortality was 3.074 times higher in patients with congenital disease compared with chronic disease patients (HR = 3.074; 95% CI: 1.577-5.995). Gender had a significant relationship with mortality; however, survival times did not differ between genders (p > 0.05). Gram-negative bacterial infections are becoming more prevalent in intensive care units, and effective control and prevention policies are needed for these infections.

Exploration of Substituted Thiazolidine-2,4-Diones: Synthesis, Characterization and Antimicrobial Evaluation

This research article presents a thorough investigation into the synthesis and assessment of a novel series of compounds- thiazolidine-2,4-diones,specifically 5-((3-methyl-5-phenoxy-1-phenyl-1H-pyrazol-4-yl)methylene)-3-((5-(4-nitrophenyl)-1,3,4-oxadiazol-2-yl)methyl)thiazolidine2,4-dione and other derivatives, focusing on their potential as antibacterial and antifungal agents. The study encompasses a wide array ofexperiments and analyses aimed at evaluating the antimicrobial activity of these compounds against various gram-positive bacteria (including Bacillus megaterium and Micrococcus spp.) and gram-negative microorganisms (such as Escherichia coli and Salmonella typhi). Furthermore, theantifungal activity of the compounds was assessed against Ganoderma spp., Aspergillus niger, A. flavus, and Penicillium spp. The structural identityand purity of the synthesized compounds were verified using different spectroscopic techniques, namely IR, 1H-NMR, 13C-NMR and massspectrometry. Following the confirmation, the compounds underwent antibacterial and antifungal screening, revealing that KS/5a and KS/5bdemonstrated remarkable antibacterial activity compared to other compounds in the series. The minimum inhibitory concentration (MIC)values of KS/5a and KS/5b were determined and found to be below the recommended threshold, indicating their potential as highly effectiveantibacterial agents.

Synthesis and Antimicrobial Activity of Novel Sulfonyl Piperidine Carboxamide Derivatives Prepared from N-Boc-Piperidine-3-carboxylic Acid via Amide Coupling

Piperidines serve as pivotal synthetic building blocks in the realm of drug design, with their derivatives forming essential parts of a wide range of drugs and alkaloids. This study presents a novel approach involving sulfonyl derivatives of piperidine-3-carboxylic acid, achieved through amide coupling with substituted sulphonyl chlorides. The synthesized compounds underwent characterization via IR, 1H NMR, 13C NMR and MS analyses. Specifically, a series of novel sulphonamides derived from 1-(tert-butoxycarbonyl)piperidine-3-carboxylic acid was synthesized, given the significance of sulphonamides as a vital drug class. Antimicrobial activity screening against both Gram-positive and Gram-negative bacteria, as well as fungi, was evaluated. The MIC concentration results revealed moderate to good activity against Gram-positive and Gram-negative microorganisms and fungal organisms.

Infections in patients with acute luekemia treated with different regimens

Patients with acute leukemia are characterized by a high risk of infectious complications due to severe neutropenia, which occurs in most cases of modern treatment regimens. Despite the improvement in cytotoxic and concomitant treatment, infectious remain the main cause of induction mortality. Aim of the study: to analyze the frequency and structure of infectious complications in patients with acute leukemia, who received different chemotherapy regimens. Material and Methods. The retrospective analysis included 40 patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). 30 patients with AML underwent 97 chemotherapy courses which included 7 + 3 program (n=53), low-intensity protocols: azacytidine in combination with venetoclax (n=26), Aza-Ida-Ara-C (n=13), low doses of cytarabine (n=3) and high-dose anti-relapse chemotherapy programs (n=2). 10 patients with ALL received 43 chemotherapy courses: ALL-2009 program (n=41), anti-relapse protocols (n=2). The frequency and duration of myelotoxic agranulocytosis, episodes of infections and the variety of microorganisms in different loci were analyzed. Statistical analysis was performed using the Statteсh v. 4.1.2 program. Results. The median duration of myelotoxic agranulocytosis was significantly higher in patients with AML, treated with 7 + 3 protocol, especially during courses of induction of remission. The most common infectious complications were pneumonia, sepsis, febrile neutropenia, and mucositis. Necrotic enteropathy and stomatitis were significantly more common for AML patients compared to ALL patients (22.7 and 7.0 %, (p=0.025); 18.6 and 2.3 %, (p=0.01), respectively). The most common etiologic factors of infections in patients with acute leukemia were gram-negative microorganisms from Enterobacteriaceae family (40.57 %) and non-fermenting bacteria (15.66 %). The detection rate of metallo-beta-lactamase-producing enterobacteria was 12.45 %. The first-line antibacterial therapy (third-generation cephalosporins with beta-lactamase inhibitor) was effective in 21.62 %, and the secondline therapy effectiveness did not exceed 8.2 %. The choice of third and subsequent line antibiotics in most cases was made taking into account the results of microbiological tests, which increased its effectiveness to 41.54 %. The greatest effectiveness was demonstrated by a combination of two carbapenems (17.07 %), and cefoperazone/sulbactam or carbapenem + co-trimoxazole (19.51 %). Conclusion. Thus, patients with acute leukemia have a high prevalence of carbapenem-resistant gram-negative infections.

SUBACUTE TOXICITY OF AN AMOXICILLIN-BASED ANTIBACTERIAL PREPARATION IN PIGS UPON REPEATED ADMINISTRATION

The article presents the results of a study of the subacute toxicity of the veterinary drug «Amoksidev 60» in pigs under conditions of repeated administration. «Amoksidev 60» is an antibacterial veterinary drug for systemic use, the active ingredient of which is amoxicillin. Amoxicillin is a semi-synthetic antibiotic from the group of aminopenicillins. It is active against gram-positive (Staphylococcus spp., Streptococcus spp., Actinomyces spp., Clostridium spp., Erysipelothrix rhusiopathiae, Listeria monocytogenes, Bacillus anthracis, Corynebacterium spp.) and some gram-negative microorganisms (Salmonella spp., Pasteurella spp., Haemophilus spp., Actinobacillus spp., Bordetella bronchiseptica, E. coli, Fusobacterium spp., Moraxella spp., Proteus mirabilis). Amoxicillin is not effective against strains that produce beta-lactamase. The mechanism of action of amoxicillin is to disrupt the formation of the cell wall of vegetative forms of bacteria by irreversible blocking of penicillin-binding proteins (PBPs) – enzymes carboxypeptidases and transpeptidases. The drug is used to treat poultry and pigs for diseases of the digestive tract and respiratory organs caused by microorganisms sensitive to amoxicillin. Oral administration of the drug «Amoksidev 60» (based on amoxicillin) to piglets with drinking water at doses of 20,0 and 100,0 mg/kg body weight for 10 days does not cause hemo-, hepato- and nephrotoxic effects on the target animals under the conditions of a subacute toxicological experiment. However, when the drug was administered at a dose of 200,0 mg/kg body weight 10 days after the start of the experiment, a decrease in the level of total hemoglobin by 6,4%, hematocrit by 5,9%, and the number of erythrocytes by 13,4% (p&lt;0,05) was recorded in the blood of pigs. At the same time, an increase in the activity of ALT, AST and urea concentration by 25,7%, 21,6% and 10,2% (p&lt;0,05), respectively, was noted in the blood serum. However, 7 days after the cessation of administration of the drug «Amoksidev 60» with drinking water in a 10-fold dose, hematological and biochemical blood parameters of pigs did not differ from control values. The prospects of further research will be focused on the analysis of the long-term effect of «Amoksidev 60» on the animal body. In particular, it is planned to investigate possible long-term toxic effects with prolonged use of the drug. In addition, an assessment of the cumulative effect during repeated courses of treatment is provided.

CHEMICAL COMPOSITION AND BIOLOGICAL ACTIVITY OF PHOLIOTA AURIVELLA (BATSCH) P. KUMM.

Objective: This study aims to determine the chemical composition of the mushroom Pholiota aurivella by investigating its antimicrobial, antibiofilm, and antioxidant activities. The potential effects of the ethanol extract of the mushroom on a total of 27 different microorganisms, including strains with multidrug resistance (MDR), were examined. Additionally, the biofilm inhibition capacity and free radical scavenging activities of the mushroom extract were tested. Material and Method: The ethanol extract obtained from the P. aurivella sample was subjected to various tests to evaluate its biological activities. Antimicrobial activity was analyzed using disk diffusion and Minimum Inhibitory Concentration (MIC) tests. Antibiofilm activity was assessed based on its capacity to inhibit biofilm formation, while antioxidant activity was tested using the DPPH method. The chemical composition was determined by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Result and Discussion: Our study reveals that P. aurivella is a promising natural agent, especially in terms of its antimicrobial and antibiofilm activities. The extract exhibited antimicrobial activity against 16 different Gram-positive and Gram-negative microorganisms. Expanding zones of inhibition were observed with increasing extract amounts in strains such as Klebsiella pneumoniae and Enterobacter aerogenes, which show multidrug resistance (MDR). In biofilm inhibition tests, the strongest effects were observed in strains of Listeria innocua and Bacillus subtilis DSMZ 1971. On the other hand, the antioxidant activity tested by the DPPH method was quite low; this can be explained by the absence of phenolic compounds in the chemical composition of the extract. GC-MS analysis identified the major components as linoleic acid (59.20%) and ethyl linoleate (17.13%). These findings indicate that P. aurivella, with its antibiofilm and antimicrobial properties, has potential for pharmaceutical applications and may offer an important natural resource for developing treatment options even against MDR pathogens.

First report of multidrug-resistant and pathogenic Plesiomonas shigelloides from endangered crested ibis (Nipponia nippon).

Plesiomonas shigelloides (P. shigelloides) is a gram-negative, thermotolerant, motile, and pleomorphic microorganism that acts as an opportunistic pathogen, capable of causing abscesses, enteric infections, and even sepsis in humans and other animals, thereby posing a threat to human and animal health worldwide. The crested ibis (Nipponia nippon) is a globally endangered avian species with a limited population and is vulnerable for various infections. To gain a better understanding of the prevalence of P. shigelloides in the endangered crested ibis, fecal samples from the crested ibis at the Xiazhu Lake Crested Ibis Breeding Research Center, China were collected and analyzed. The results confirmed that 45.6% (36/79) of the fecal samples tested positive for P. shigelloides. Antibiotic susceptibility testing showed that 27.8% (10/36) of P. shigelloides isolates were multidrug-resistant, with resistance to ampicillin and amikacin being 100% and 77.8%, respectively. Subsequently, ten representative isolates were subjected to whole genome sequencing, and resistance and virulence genes were analyzed. The evolutionary tree of the genomes show that these strains have different origins, with one strain closely related to a strain from human. Finally, the pathogenicity experiment demonstrated that several strains exhibit pathogenicity in both mice and waterfowl, with two strains displaying lethal pathogenicity in mice. To the best of our knowledge, this is the first report of multidrug-resistant and pathogenic P. shigelloides isolated from the crested ibis, suggesting a potential threat to this endangered species and broader public health implications.

Early post-trauma wound microbiota and its association with pain outcomes and mental health in combat-related extremity injuries: a prospective analysis.

Given that many armed conflicts are currently ongoing worldwide, a thorough study of issues related to providing medical care for the wounded is essential. We included 45 participants aged 20-60 years with limb injuries in our study. The participants were surveyed using a visual analog pain scale, the PHQ-9, and the PTSD-5. We formed three groups: the first group included patients with limb amputations, the second group consisted of patients with limb trauma, and the third group involved patients with limb burns. We found that the average pain level in Group 1 was higher, though statistical significance was not achieved (p > 0,05). According to the PHQ-9, all participants exhibited depressive symptoms of varying severity. In the trauma group, patients reported fewer PTSD symptoms. Among the amputees, a significant predominance of Gram-negative microorganisms was noted. The correlation between the slightly higher pain levels and the significant predominance of Gram-negative flora in amputee patients was negative (P > 0.05). In the amputee group, there was a trend toward higher mean pain scores compared to the other groups (p > 0,05). The same presence and distribution of depressive and PTSD symptoms were observed across all groups. Correlation analysis between pain intensity and contamination with Gram-negative bacteria did not reveal a relationship between these two variables. The study requires a larger patient sample. Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella oxytoca, and Proteus mirabilis were found more frequently among all patients.

Lawsonia inermis extract: Antibacterial, anticancer and antioxidant properties

Henna, scientifically known as Lawsonia inermis, is long used for its therapeutic benefits in several civilisations. This study examines the antibacterial, anticancer, and antioxidant properties of the leaf extract from L. inermis. The phytochemical study indicated the existence of alkaloids, flavonoids, glycosides, phenolic compounds, and tannins. GC–Mass Spectrometry detected notable bioactive chemicals, including tetracosamethyl-cyclododecasiloxane and cyclohexasiloxane. The extracts demonstrated strong antioxidant properties, as evidenced by their values of 254.32 and 121.25%, as well as their high FRAP values, demonstrating their effective ability to scavenge radicals. The antibacterial effectiveness, assessed by the disc-diffusion technique, demonstrated substantial inhibition zones against both Gram positive and Gram-negative microorganisms. The MTT experiment exhibited significant anticancer efficacy against MCF‑7 breast cancer cell lines, with an IC50 value of 1.682 μg/mL. The results indicate that extracts from L. inermis contain significant bioactive substances that have the potential to be utilised in the development of innovative medications aimed at addressing oxidative stress, bacterial infections, and cancer.

Antifouling Activity of Bottlebrush Network Hydrogels.

Mitigating the attachment of microorganisms to polymer biomaterials is critical for preventing hospital-acquired infections. Two chemical strategies to mitigate fouling include fabricating fouling-resistant surfaces, which typically present hydrophilic polymers, such as polyethylene glycol (PEG), or creating fouling-release surfaces, which are generally hydrophobic featuring polydimethylsiloxane (PDMS). Despite the demonstrated promise of employing PEG or PDMS, amphiphilic PEG/PDMS copolymer materials remain understudied. Here, for the first time, we investigated if phase-separated amphiphilic copolymers confounded microbial adhesion. We used bottlebrush amphiphilic PEG/PDMS co-networks and homopolymer networks to study bacterial adhesion across a library of gels (ϕPEG = 0.00, 0.21, 0.40, 0.55, 0.80, and 1.00). Hydrated atomic force microscopy measurements revealed that most of the gels had low surface roughness, less than 5 nm, and an elastic modulus of ∼80 kPa. Interestingly, the surface roughness and elastic modulus of the ϕPEG = 0.40 gel were twice as high as those of the other gels due to the presence of crystalline domains, as confirmed using polarized optical microscopy on the hydrated gel. The interactions of these six well-characterized gels with bacteria were determined using Escherichia coli K12 MG1655 and Staphylococcus aureus SH1000. The attachment of both microbes decreased by at least 60% on all polymer gels versus the glass controls. S. aureus adhesion peaked on the ϕPEG = 0.40, likely due to its increased elastic modulus, consistent with previous literature demonstrating that modulus impacts microbial adhesion. These findings suggest that hydrophilic, hydrophobic, and amphiphilic biomaterials effectively resist the early attachment of Gram-negative and Gram-positive microorganisms, providing guidance for the design of next-generation antifouling surfaces.

Acinetobacter baumannii: Mechanisms of Antimicrobial Resistance

Gram-negative non-fermenting bacteria Acinetobacter baumannii are a common cause of severe complications (pneumonia, bacteremia, sepsis) in the clinic of internal diseases, especially in patients with weakened immune system: 3,2% of bacteremia and sepsis cases are associated with A. baumannii, with mortality rate 26–91%. A. baumannii has the ability to rapidly acquire antimicrobial resistance. In recent decades, strains with multiple resistance to antimicrobial drugs have emerged, including beta-lactams, including carbapenems, aminoglycosides, and fluoroquinolones, which are the drugs of choice in the treatment of severe hospital infections caused by Gram-negative microorganisms. Globally, about 45% of A. baumannii isolates are multidrug-resistant, with multidrug resistance reaching 90% in the Middle East, Southern Europe, and North Africa, and 60% in China. The prevalence of polyresistant strains of A. baumannii in patients with nosocomial pneumonia associated with mechanical ventilation is estimated at 80%. The main mechanisms of antimicrobial resistance of the pathogen are impaired permeability of the cell wall to antibiotics as a result of modification of porin proteins, activation of efflux pump systems, production of enzymes that destroy antibacterial drugs, and biofilm formation. The review examines the molecular basis of the formation of resistance to antibacterial drugs in A. baumannii.

Determination of pathogens in deep surgical site infections following sinus tarsi approach calcaneal fracture surgery via open reduction internal fixation or primary arthrodesis - Implications for prophylaxis and treatment.

Determination of pathogens in deep surgical site infections following sinus tarsi approach calcaneal fracture surgery via open reduction internal fixation or primary arthrodesis - Implications for prophylaxis and treatment.

Molecular Characterization of Gram-Negative Bacilli Isolated from a Neonatal Intensive Care Unit and Phenotypic and Molecular Detection of ESBL and Carbapenemase.

The increase in the rates of multidrug-resistant bacteria in healthcare environments has been recognized as a global public health problem. In view of the scarcity of data on the neonatal population, this study aimed to provide information on the genotypic and epidemiological characteristics of Gram-negative microorganisms isolated from colonization and infection sites in neonates admitted to a tertiary university center of high complexity. Enterobacterales and non-fermenting Gram-negative bacilli previously collected in a prospective cohort study were submitted to genotypic identification, detection of extended-spectrum β-lactamases (ESBL), carbapenemases and biofilm production, detection of specific virulence markers in Pseudomonas aeruginosa, and typing by pulsed-field gel electrophoresis. The data found here revealed higher rates of infection by Klebsiella spp. and Serratia marcescens that caused bloodstream infection and pneumonia, respectively. In this study, high biofilm production was observed, with 95.0% of Enterobacterales and 100% of non-fermenting Gram-negative bacilli being producers. Most of the P. aeruginosa isolates carried pathogenicity factors such as alginate, hemolytic phospholipase C, exotoxin A, and rhamnolipids. The phenotypic analysis of ESBL revealed that 16 (5.3%) isolates produced these enzymes. Four of these isolates (66.7%) carried the CTX-M-9 gene, three (50%) carried the TEM gene, and one (16.7%) was positive for the SHV and CMY-2 genes. Univariate and multivariate Cox regression analyses were used to identify risk factors for colonization and infection by Gram-negative microorganisms. The results of multivariate analysis revealed that biofilm production by these microorganisms was associated with the persistence of colonization by the same pathogen in the newborn and increased by 75% the daily probability of the newborn developing infection. The production of ESBL also increased the daily probability of infection by 46.8 times. Enterobacterales showed average biofilm production, while the majority of non-fermenting Gram-negative bacilli were strong producers. The present data increase our knowledge of the molecular epidemiology of important Enterobacterales species, with emphasis on ESBL-producing Enterobacter cloacae and Klebsiella pneumoniae with emerging epidemiological potential in the neonatal intensive care unit of a tertiary university hospital. Furthermore, the results highlight the need for the monitoring and implementation of control measures and for restricting the use of broad-spectrum antibiotics.

The efficient chitosan–polythiophene–graphene oxide bionanocomposite with enhanced antibacterial activity, dye adsorption ability, mechanical and thermal properties

Water pollution is the most serious environmental issues due to toxic impurity such as dye and pathogenic microorganisms. The main goal of the present study is to produce a novel ternary chitosan–polythiophene–graphene oxide (CS–PTh–GO) bionanocomposites using the intercalation of GO into CS through solution mixing process followed by the in-situ polymerization of thiophene for removal of dye and killing microorganisms from an aqueous solution. The fabricated CS–PTh–GOs were characteristically examined via FTIR, XRD, SEM, TEM, TGA, tensile analysis and subsequently applied for adsorption of cationic dyes such as methylene blue (MB) in the dark or under light and killing the growth of Gram-positive and Gram-negative microorganisms. The data revealed that presence of PTh–GO enhanced the surface roughness, tensile strength, thermal stability, adsorption characteristics and antibacterial activity. The CS–PTh–GO showed 97% dye removal of MB in 50 min. Ultimately, the CS–PTh–GO bionanocomposites analysis against the growth of Staphylococcus aureus, and Escherichia coli manifesting a minimum inhibitory concentration (MIC) of 5 µg/mL, respectively. Thus, the CS–PTh–GO bionanocomposite has the potential to use as an efficient adaptable antimicrobial and dye absorbent of organic dyes in industrial wastewater.