Common Gram-positive Bacteria Research Articles

Folic acid functionalized Ag@MOF(Ag) decorated carboxymethyl starch nanoparticles as a new doxorubicin delivery system with inherent antibacterial activity

Considering the benefits of controlled drug delivery in cancer treatment, as well as the importance of biological macromolecules in this area, herein, the pre-synthesized carboxymethyl starch (CMS) was converted to CMS nanoparticles (CMS NPs) in one easy nanoprecipitation way. Thereafter, the Ag@MOF(Ag) was in situ synthesized in the presence of pre-prepared CMS NPs (CMS NPs/Ag@MOF(Ag)). Eventually, the functionalization with folic acid (FA) obtained the CMS NPs/Ag@MOF(Ag)-FA. The success of the accomplished process was approved by doing several techniques, including FT-IR, XRD, EDX, AFM, etc. The SEM analysis showed a combination of rod-like and spherical-like morphology for the fabricated bio-nanocomposite. The generated CMS NPs/Ag@MOF(Ag)-FA with a surface area of 10.595 m2/g displayed a pore size of 13.666 nm and 82.99 % of doxorubicin (DOX) loading efficiency (DOX@CMS NPs/Ag@MOF(Ag)-FA). The 38.46 % and 58.19 % of loaded DOX were released respectively within 240 h at pH 7.4 and pH 5.0, referring to the pH-responsivity of the constructed system. 27.25 % of inhibitory effects on HeLa cells were obtained for the drug-loaded bio-nanocomposite. The CMS NPs/Ag@MOF(Ag)-FA also displayed an inherent antibacterial activity towards two common gram-negative and gram-positive bacteria. All of these results can contribute to developing polysaccharide-based porous systems in controlled cancer therapy.

The novel peptide adjuvants potentiate antimicrobial properties of melittin against methicillin-resistant Staphylococcus aureus and their efficacy as potential food preservatives

Melittin, a notable antimicrobial peptide (AMP), shows great potential in food preservation due to its robust antimicrobial properties, especially when facing multidrug-resistant (MDR) bacteria. However, developing melittin as a food preservative is limited by its poor cell selectively, necessitating innovative strategies are needed to address the application bottleneck of melittin. Here, we characterize two linear peptide adjuvants (3-WP and 9-RP), which exhibited obvious synergistic effects with melittin against common Gram-positive bacteria. Their synergistic effects potentiated antimicrobial efficacy of melittin against methicillin-resistant Staphylococcus aureus (MRSA), while reduced the required dose of melittin for antimicrobial activity, which is contributed to improving the cell selectively of melittin. Mechanistically, 3-WP disrupted cell wall membrane permeability, induced reactive oxygen species (ROS) production, and inhibited energy metabolism. The 3-WP/melittin combination exhibited favorable antimicrobial effects in food storage contexts. Our findings highlighted the great potential of 3-WP as a peptide adjuvant of melittin for combating MDR-associated foodborne diseases and developing safe and effective peptide-based bio-preservatives.

In vitro activities of eravacycline against clinical bacterial isolates: a multicenter study in Guangdong, China.

Eravacycline (ERV), a novel tetracycline derivative, exhibits broad-spectrum antibacterial activity, but data on the bacterial activity against Chinese bacterial isolates are very scarce. This study aims to evaluate the activity of eravacycline against the common Gram-positive and Gram-negative bacteria isolates in Guangdong, China. The clinical isolates were collected from four centers between 1 November 2023 and 31 January 2024, and the susceptibility of eravacycline (MIC50, MIC90, and MIC) was determined using broth microdilution as a reference method and E-TEST strips to evaluate their consistency. A total of 594 strains were collected from the four centers, including Staphylococcus aureus (n = 126), Enterococcus faecalis (n = 58), Enterococcus faecium (n = 29), Klebsiella pneumoniae (n = 136), Escherichia coli (n = 187), and Acinetobacter baumannii (n = 58). The MIC50 and MIC90 (mg/L) of eravacycline were 0.12 and 1 for S. aureus, 0.06 and 0.12 for E. faecalis, 0.06 and 0.5 for E. faecium, 0.25 and 0.5 for E. coli, 0.5 and 2 for K. pneumoniae, and 0.25 and 2 for A. baumannii. Based on the FDA and EUCAST breakpoints, the susceptibility of eravacycline against S. aureus was 46.03% vs. 83.33%, 56.90% vs. 94.93% against E. faecalis, and 62.07% vs. 79.31% in E. faecium. The susceptibility rates of E. coli and K. pneumoniae were 90.37% and 58.09, respectively. To evaluate the performance between the broth microdilution test (BMD) and ETEST methods, we compared essential agreement (EA), categorical agreement (CA), very major error (VME), and major error (ME). The results demonstrated that compared with BMD, eravacycline measured by ETEST had higher VME and ME referring to FDA breakpoints than EUCAST breakpoints in the Gram-positive isolates. Since there were no intermediate breakpoints for the eravacycline, the MIC values measured by the ETEST method might result in lower CA and higher VME and ME. This study provides MIC values of eravacycline against Gram-positive and Gram-negative pathogens in four hospitals in Guangdong Province, and eravacycline is an effective therapeutic candidate for common bacteria.

Brain abscess caused by Streptococcus pyogenes with atypical symptoms: a case report and literature review

BackgroundStreptococcus pyogenes is a common gram-positive bacterium, belonging to group A Streptococcus (GAS), and is responsible for causing a range of clinical conditions. Brain abscess caused by GAS is uncommon in pediatric infectious diseases, and GAS brain abscess without acute infectious symptoms has been rarely reported.Case presentationWe present a case of one GAS brain abscess in a previously healthy child with unusual clinical manifestations of decreased muscle strength in the left limbs. The right frontal lobe mass lesion was resected using a microscope-based neuronavigation system. A sole defectively beta-hemolytic Streptococcus pyogenes was isolated from the lesion. The patient’s peripheral blood whole-exome and the pathogen’s whole-genome sequencing were performed respectively, revealing a heterozygous mutation in the interferon regulatory factor-8 (IRF8) gene in the patient and lack of hyaluronic acid capsules in Streptococcus pyogenes (genotype emm22). The patient eventually recovered after prompt surgical drainage of the abscess and appropriate antibiotic treatment.ConclusionsIt is important to pay attention to Streptococcus pyogenes brain abscesses with mild clinical manifestations. Upon reviewing all the cases of pediatric GAS brain abscess reported in the published literature, we discovered that early diagnosis and treatment are crucial factors that impact the prognosis of GAS brain abscess.

Microbial Spectrum, Antimicrobial Resistance, and Prevalence of MDR/XDR Pathogens in Medical Device-Associated Infections

Background: Medical device-associated infections (MDAIs) are a major healthcare concern due to their high morbidity, mortality, and rising prevalence of MDR and XDR bacteria. This study examined the microbiological composition, antimicrobial susceptibility, and prevalence of MDR/XDR infections in MDAI patients at Dr. D.Y. Patil Medical College, Pune. Methods: One-year retrospective research included 100 MDAI patients. Antimicrobial susceptibility testing was done on microbial isolates from blood, urine, and wound swabs according to CLSI standards. The prevalence of MDR and XDR pathogens was determined. Results: Escherichia coli (30%) and Klebsiella pneumoniae (20%) caused most infections, while Staphylococcus aureus (25%) was the most common Gram-positive bacteria. Antimicrobial susceptibility testing showed that 40% of the isolates were MDR and 15% were XDR. Klebsiella pneumoniae had the highest resistance rate (70%), followed by Pseudomonas aeruginosa. Conclusion: The study shows that MDAIs are dominated by MDR and XDR infections, mainly Gram-negative bacteria, making therapy difficult. These findings highlight the critical need for improved infection control, antimicrobial stewardship, and regular surveillance to address medical device-associated resistance infections. Keywords: Medical device infections, multidrug-resistant, extensively drug-resistant organisms, antimicrobial susceptibility, microbiological profile, healthcare-associated infections.

Value of metagenomic next-generation sequencing in the diagnosis of native pyogenic spinal infections: a multicenter, retrospective observational study

Background contextThe etiological diagnosis of pyogenic spinal infection is crucial for its precise antibiotic treatment. Traditional methods of detection are often slow and ineffective. In recent times, metagenomic next-generation sequencing (mNGS) has revolutionized pathogen detection, offering a more effective approach to disease management. PurposeComparing mNGS with microbial culture to comprehensively explore the diagnostic value of mNGS in pyogenic spinal infections. DesignA multicenter, retrospective observational study. Patient sampleIn a multicenter retrospective observational study, we analyzed the data from 301 patients admitted in 4 selected hospitals with pyogenic spinal infections from December 2019 to February 2024. Outcome measuresIdentification of pathogenic bacteria in patients. MethodsObtain blood and lesion tissue or pus samples from the enrolled patients for microbial culture, serological and hematological laboratory tests, pathological examination, and mNGS analysis, followed by a comparative analysis of the results. ResultsIn our cohort of 301 cases of clinically diagnosed pyogenic spinal infections, 242 yielded etiological evidence. The most common gram-positive bacterium was Staphylococcus aureus, and the most common gram-negative bacterium was Escherichia coli. mNGS showed a significantly higher rate of detection (77.9%) compared with microbial culture (27.2%) with a notable difference (X² = 140.17, P < 0.001). In culture-negative samples, mNGS could detect pathogens in 73.1% of cases, and in culture-positive samples, it could detect pathogens in 91.5% of cases with 94.7% genus-level concordance. mNGS provided faster results (24–48 h) compared with the culture method (2–7 days). ConclusionsmNGS serves as a valuable supplement to the culture method and shows potential in identifying the causative pathogen in native pyogenic spinal infections.

Aetiology and Prognostic Significance of Postoperative Urinary Tract Infections in Patients with Cervical Cancer.

This study aimed to investigate the risk factors for urinary tract infections (UTIs) in patients with cervical cancer (CC) following radical surgery, and analyse the etiological distribution and prognostic implications of these infections. A retrospective analysis was conducted on the clinical data of 168 patients with CC who underwent radical surgery at our hospital between January 2021 and December 2023. Postoperative UTI incidence and associated risk factors were analysed. Postoperative urine samples were collected under sterile conditions for pathogen culture to analyse pathogen distribution. Patients were classified into poor and good prognosis groups based on their health status within one month of treatment. The relationship between pathogen distribution and prognosis in patients with CC and postoperative UTIs was analysed. The incidence of postoperative UTIs was 35.12% (59 cases). Among these patients, 84 pathogen strains were detected in urine samples, including 54 of gram-negative bacteria, 26 of gram-positive bacteria, and four of fungi. The single-factor analysis identified age, diabetic status, menopausal status, tumour diameter, surgical duration, intraoperative blood loss volume, duration of ureteral catheterisation, and postoperative urinary retention as potential risk factors. The multifactorial analysis confirmed age, diabetic status, operation duration, intraoperative blood loss volume, duration of ureteral catheterisation, and postoperative urinary retention as independent risk factors. The distribution of Klebsiella pneumoniae (K. pneumoniae) significantly differed between the study groups, while other pathogens showed no significant difference. UTIs in patients with CC post-radical surgery are primarily caused by gram-negative bacteria, mainly Escherichia coli and K. pneumoniae. K. pneumoniae is predominant in patients with a poor prognosis, while Enterococcus spp. is the most common gram-positive bacterium observed.

Evaluation of Antibiotic Sensitivity in Methicillin-Resistant Staphylococcus aureus Isolates From Clinical Specimens in a Tertiary Care Hospital.

Common Gram-positive bacteria Staphylococcus aureus can cause infections ranging from minor skin conditions to serious illnesses like sepsis.Methicillin-resistant S. aureus (MRSA) emerged in the 1960s and now causes over 50% of hospital infections. In India, MRSA prevalence ranges from 25% in the west to 50% in the south. Contributing factors include prolonged hospital stays and indiscriminate antibiotic use. This study investigates the prevalence and antibiotic resistance patterns of MRSA in clinical isolates from a hospital in Karad. MRSA's resistance to multiple antibiotics, including vancomycin, poses significant treatment challenges, with limited therapeutic options such as vancomycin, linezolid, daptomycin, and teicoplanin remaining effective. The antibiotics mentioned provide a broader context for understanding MRSA resistance. In this study, only those specifically relevant to the hospital's data have been included in detail in the result table antibiogram of MRSA. A two-year laboratory-based analysis of MRSA strains in a hospital that provides tertiary care was conducted to assess their antibiotic susceptibility profiles. In all, 100 isolates of MRSA were examined for patterns of antibiotic susceptibility in various clinical specimens. Among these 41 (41%) were from pus samples, 18 (18%) from wound swabs/discharge, 15 (15%) from urine, 13 (13%) from blood, 4% fromsputum, and 3% fromtips were found to have smaller percentages than umbilical swabs (2 (2%)) and tissue (1 (1%)) and vaginal swabs( 1 (1%)) and sinus tract samples (1 (1%)). The frequency of MRSA strains was more in males (59%). Linezolid showed the highest sensitivity at 86%. This studyhighlights the growing challenge of MRSAand other resistant bacteria in hospital settings, complicating treatment choices. Effective MRSA​​​​​​​ management requires stringent antibiotic policy, infection control procedures, and thorough susceptibility testing. These strategies are critical to preserving viable treatment options and combating antibiotic resistance in healthcare environments.

Computational and in vitro analyses of the antibacterial effect of the ethanolic extract of Pluchea indica L. leaves.

The most common gram-negative, Escherichia coli, and gram-positive bacteria, Bacillus spp., have evolved different mechanisms that have caused the emergence of multi-drug resistance. As a result, drugs that block the bacterial growth cycle are needed. Here, in silico and in vitro studies were performed to assess compounds in the Pluchea indica leaf extract, a medicinal plant, that can inhibit bacterial proteins. Briefly, P. indica leaves were extracted using ethanol. The crude extract was then subjected to gas chromatography-mass spectrometry for metabolite screening. Molecular docking simulations with rhomboid protease (Rpro) (Protein data bank ID number: 3ZMI from E. coli and filamenting temperature-sensitive mutant Z (FtsZ) protein data bank ID number: 2VAM from Bacillus subtilis were performed. Moreover, the well diffusion method was used to confirm the antibacterial activity of P. indica leaf extract. A total of 10 compounds were identified in the P. indica extract and used for computational analysis. Based on drug-likeness prediction, P. indica compounds may be drug-like molecules. Binding affinity tests indicated that 10,10-Dimethyl-2,6-dimethylenebicyclo(7.2.0)undecan-5.β.-ol and 11,11-Dimethyl-4,8-dimethylenebicyclo(7.2.0)undecan-3-ol had the most negative values. Accordingly, these compounds may be potential ligands that bind to bacterial proteins. The root mean square fluctuation values was <2 Å, indicating stable fluctuation binding for the ligand-protein complex. According to in vitro antibacterial assays, a high concentration (50%) of the P. indica extract markedly inhibited E. coli and B. subtilis, with inhibitory zone diameters of 31.86±1.63 and 21.09±0.09 mm, respectively. Overall, the compounds in the P. indica leaf extract were identified as functional inhibitors of E. coli and B. subtilis proteins via in silico analysis. This may facilitate development of antibacterial agents.

ACOD1 mediates Staphylococcus aureus-induced inflammatory response via the TLR4/NF-κB signaling pathway

Staphylococcus aureus (SA) is a common Gram-positive bacterium that activates inflammatory cells, expressing various cytokines and inducing an inflammatory response. Recent research revealed aconitate decarboxylase 1 (ACOD1) as a regulator of the immune response through various metabolic pathways, playing a dual role in the inflammatory response. However, the mechanism by which ACOD1 participates in the regulation of SA-induced inflammatory responses in macrophages remains unknown. Therefore, this study aims to investigate the function and underlying regulatory mechanisms of ACOD1 in SA-induced inflammatory response. This study reveals that SA induced a macrophage inflammatory response and upregulated ACOD1 expression. ACOD1 knockdown significantly inhibited SA-induced macrophage inflammatory response, attenuated SA-induced nuclear envelope wrinkling, and plasma membrane rupture, and suppressed the TLR4/NF-κB signaling pathway. Furthermore, ACOD1 knockdown reduced the inflammatory response and alleviated lung tissue injury and cellular damage, leading to decreased bacterial loads in the lungs of SA-infected mice. Collectively, these findings demonstrate that SA induces an inflammatory response in macrophages and increases ACOD1 expression. ACOD1 enhances SA-induced inflammatory responses via the TLR4/NF-κB signaling pathway. Our findings highlight the significant role of ACOD1 in mediating the inflammatory response in SA-infected macrophages and elucidate its molecular mechanism in regulating the SA-induced inflammatory response.

Trends in Causative Organisms and Antimicrobial Resistance in Late-onset Neonatal Sepsis.

The aim of this study was to evaluate the antibiotic resistance of microorganisms isolated in cases of culture-positive nosocomial late-onset neonatal sepsis in the neonatal intensive care unit. Infants admitted to our neonatal intensive care unit between October 2015 and June 2022 were retrospectively screened. A total of 458 different cultures from 386 sepsis incidents in 250 infants were analyzed. Over an 8-year period, 407 cases of culture-positive nosocomial late-onset neonatal sepsis were reviewed in a total of 4244 infants. Twenty-one cases were excluded due to insufficient data. The incidence of culture-positive nosocomial sepsis was 6.3%. Coagulase-negative Staphylococcus and Staphylococcus aureus were the most common gram-positive bacteria found in cultures. Resistance to ampicillin and cephalosporin treatments was high, while resistance to vancomycin, teicoplanin, and linezolid was low. Klebsiella spp. were the most frequent gram-negative bacteria isolated in cultures and showed high resistance to non-carbapenembased regimens. The only fungal microorganisms isolated in cultures were Candida spp., which had a high mortality rate despite their low resistance profile. The mortality rate due to nosocomial sepsis was 19.6%. Our study demonstrated that microorganisms and their antibiotic resistance profiles changed over time in the newborn intensive care unit. Gram-negative pathogens exhibited high antibiotic resistance, while fungi had high mortality rates. It is essential to adjust empirical antibiotic regimens for nosocomial sepsis based on thorough surveillance.

Detection of Methicillin Resistance and Methicillin Sensitive Staphylococcus Aureus from Various Clinical Specimens in Tertiary Care Hospital

INTRODUCTION : Staphylococcus aureus is one of the most common Gram-positive pyogenic bacteria responsible for variety of disease. Methicillin resistance Staphylococcus aureus (MRSA) has become a major cause of hospital associated infection. MRSA can also acquire resistance to multiple alternative antimicrobials, further complicating treatment of infection. For the severe infection of MRSA, vancomycin considered one of the last treatments relatively new agents such as Linezolid and Daptomycin is used. MATERIAL AND METHODS: 141 Staphylococcus aureus were isolated from samples such as pus, sputum, urine, blood, body fluid, wound swab received in microbiology department of Krishna institute of medical sciences, karad. They were conformed by microscopy, culture, and biochemical reaction. Then MRSA were detected by using disc diffusion test using cefoxitin (30ug) disc. RESULTS: Majority of Staphylococcus aureus were isolated from pus samples 71 (50.35%). Out of 141 isolates, 81 (57.44%) were MRSA and 60 (42.55%) were MSSA. In MRSA and MSSA isolates, higher percentage of resistance was seen in Penicillin 78 (96.29%) and 55 (90.16%) respectively. CONCLUSION :The present study emphasized the burden of MRSA in patients at our hospital. The determination of antibiotic sensitivity patterns and screening for MRSA among Staphylococcus aureus isolates are important for controlling the clinical Staphylococcal infection. The antibiotic sensitivity pattern helps in judicious use of antimicrobial agents.

Bacterial etiology and antimicrobial resistance pattern of pediatric bloodstream infections: a 5-year experience in an Iranian referral hospital

BackgroundBloodstream infections (BSI) are the major cause of morbidity and mortality in children in developing countries. The purpose of the current study was to establish the antimicrobial susceptibility pattern of bacterial isolates from bloodstream infections at Children’s Medical Center Hospital (CMC), Tehran, Iran.MethodsWe retrospectively recorded all positive blood cultures and antimicrobial susceptibility of all bloodstream isolates among children admitted to CMC, during 5 years. Specimen culture, bacterial identification, and antimicrobial susceptibility testing were performed according to standard laboratory methods.ResultsFrom 3,179 pathogens isolated from the blood cultures 2,824 bacteria were cultured, with 1,312 cases being identified as Gram-positive bacteria (46%) and 1,512 cases as Gram-negative bacteria (54%). The most common Gram-negative bacteria isolated were as follows: Pseudomonas spp. (n = 266, 17.6%), Klebsiella pneumoniae (n = 242, 16%), Stenotrophomonas maltophilia (n = 204, 13.5%), Enterobacter spp. (n = 164, 10.8%), Escherichia coli (n = 159, 10.5%), Pseudomonas aeruginosa (n = 126, 8.3%), Serratia marcescens (n = 121, 8%), and Acinetobacter baumannii (n = 73, 4.8%). The most common Gram-positive bacteria isolated were coagulase-negative staphylococci (CONS) (n = 697, 53%), Streptococcus spp. (n = 237, 18%), Staphylococcus aureus (n = 202, 15%) and Enterococcus spp. (n = 167, 12.7%). 34% of bacterial strains were isolated from ICUs. The rates of methicillin resistance in S. aureus and CONS were 34% and 91%, respectively. E. coli isolates showed high resistance to cefotaxime (84%). All isolates of K. pneumoniae were susceptible to colistin and 56% were susceptible to imipenem. P. aeruginosa isolates showed high susceptibility to all antibiotics.ConclusionsOur findings emphasize the need of clinicians having access to up-to-date bacterial susceptibility data for routinely prescribed drugs. Continuous monitoring of changes in bacterial resistance will aid in the establishment of national priorities for local intervention initiatives in Iran. The increased risk of BSI caused by antibiotic-resistant organisms, emphasizes the significance of implementing appropriate antibiotic prescribing regulations and developing innovative vaccination techniques in Iran.

Antibacterial activities of honey bee against gram-positive bacteria isolated from urine

The medicinal benefits of honey have long been recorded in ancient days as a solution for various ailments and infections. This study x-rayed the effects of honey on common gram-positive bacteria isolated from urine. The study evaluated the in vitro susceptibility of two gram positive bacteria strains, isolated from urine of students of Nnamdi Azikiwe University, Awka Anambra state, Nigeria. The end point was achieved via macroscopic, microscopic methods and biochemical examinations which includes: gram staining, urease, catalase, coagulase testing to a hsoney sample. The evaluation of the antibacterial activity was ascertained by the agar diffusion well method. The results obtained in this study proved that the honey sample exhibited potent antibacterial activity against the tested strains, the zone of inhibition was at a mean value of 20.5 mm and 29.5 mm respectively at 100% concentration of honey. Staphylococcus epidermidis was found to be less susceptible than Enterococcus faecalis with a mean inhibition zones being 29.5 mm. This contribution has provided a broad overview of the antibacterial activity of honey and shown that honey bee has great potential for therapeutic use as an alternative therapy for infections caused by the isolates.

Spectrum and antibiotic sensitivity of bacterial keratitis: a retrospective analysis of eight years in a Tertiary Referral Hospital in Southwest China.

The objective of this study was to investigate the epidemiological characteristics, distribution of isolates, prevailing patterns, and antibiotic susceptibility of bacterial keratitis (BK) in a Tertiary Referral Hospital located in Southwest China. A retrospective analysis was conducted on 660 cases of bacterial keratitis occurring between January 2015 and December 2022. The demographic data, predisposing factors, microbial findings, and antibiotic sensitivity profiles were examined. Corneal trauma emerged as the most prevalent predisposing factor, accounting for 37.1% of cases. Among these cases, bacterial culture results were positive in 318 cases, 68 species of bacteria were identified. The most common Gram-Positive bacteria isolated overall was the staphylococcus epidermis and the most common Gram-Negative bacteria isolated was Pseudomonas aeruginosa. Methicillin-Resistant Staphylococci accounted for 18.1% of all Gram-Positive bacteria. The detection rate of P. aeruginosa showed an increasing trend over time (Rs=0.738, P=0.037). There was a significant decrease in the percentage of Gram-Negative microorganisms over time (Rs=0.743, P=0.035). The sensitivity of Gram-Positive bacteria to linezolid, vancomycin, tigecycline, quinupristin/dalfopristin, and rifampicin was over 98%. The sensitivity rates of Gram-Negative bacteria to amikacin, meropenem, piperacillin/tazobactam, cefoperazone sodium/sulbactam, ceftazidime, and cefepime were all above 85%. In patients with a history of vegetative trauma, the possibility of BK should be taken into account in addition to the focus on fungal keratitis. The microbial composition primarily consists of Gram-Positive cocci and Gram-Negative bacilli. Among the Gram-Positive bacteria, S. epidermidis and Streptococcus pneumoniae are the most frequently encountered, while P. aeruginosa is the predominant Gram-Negative bacteria. To combat Gram-Positive bacteria, vancomycin, linezolid, and rifampicin are considered excellent antimicrobial agents. When targeting Gram-Negative pathogens, third-generation cephalosporins exhibit superior sensitivity compared to first and second-generation counterparts. As an initial empirical treatment for severe cases of bacterial keratitis and those unresponsive to fourth-generation fluoroquinolones in community settings, the combination therapy of vancomycin and tobramycin is a justifiable approach. Bacterial keratitis can be better managed by understanding the local etiology and antibacterial drug susceptibility patterns.

Epidemiologic analysis of antimicrobial resistance in hospital departments in China from 2022 to 2023

Bacterial drug resistance monitoring in hospitals is a crucial aspect of healthcare management and a growing concern worldwide. In this study, we analysed the bacterial drug resistance surveillance in our hospital from 2022 Q1 to 2023 Q2. The main sampling sources were respiratory, blood, and urine-based, and the main clinical infections were respiratory and genitourinary in nature. Specimens were inoculated and cultured; bacterial strains were isolated using a VITEK® 2 Compact 60-card automatic microorganism identifier (bioMerieux, Paris, France) and their matching identification cards were identified, and manual tests were supplemented for strain identification. The most common Gram-positive bacteria detected were Staphylococcus aureus, followed by Enterococcus faecalis (E. faecalis), Staphylococcus epidermidis (S. epidermidis), and Staphylococcus haemolyticus (S. haemolyticus). The most common Gram-negative bacteria detected were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The most prevalent multidrug-resistant bacteria were those producing extended-spectrum beta-lactamases, followed by methicillin-resistant Staphylococcus aureus, followed by carbapenem-resistant Enterobacterales. This study suggests that the prevention and control of infections in the respiratory and genitourinary systems should be the focus of anti-infective work and that the use of antimicrobials should be reduced and regulated to prevent the emergence and spread of resistant bacteria.

Healthcare-Associated Infections' Characteristics Among Burn Patients and Risk Factors of Mortality: A Study Based on Data From a Tertiary Center in Iran: Nosocomial Infections Among Burn Patients.

Background: Burn patients are more likely to get healthcare-associated infections (HAIs). The current study aimed to investigate the characteristics of HAI and mortality risk factors among burn patients admitted to a tertiary center in Iran. Methods: A retrospective study was conducted in 2021 on burn patients who developed HAI after hospitalization in a tertiary center in Ahvaz, Iran. The records of patients admitted and managed between March 2019 and March 2020 were reviewed. Statistical analysis was carried out using IBM SPSS Version 26, with p < 0.05 considered statistically significant. Results: Of the 1,659 admitted patients, 395 (23.8%) developed HAI during the study period. After excluding patients with incomplete medical records and those with fungal or viral infections, 363 patients remained. The majority of these cases occurred in male patients. The most common type of HAI was burn wound infection (56.2%). Patients were mainly affected by Gram-negative bacteria, Pseudomonas aeruginosa (39.7%), while the most common Gram-positive bacteria was Staphylococcus epidermididis (9.6%). The most common antibiotic resistance among P. aeruginosa-infected patients was reported against imipenem, followed by gentamicin and ciprofloxacin; however, the mentioned organism was mainly sensitive to colistin. Gender, age, bloodstream infection (BSI), ventilator-associated infection (VAI), ICU admission, and total burned surface area (TBSA) resulted in 3.585, 1.028, 2.222, 7.469, 5.278-, and 1.031 times higher mortality rates, respectively. Conclusion: Female gender, advanced age, BSI, VAI, and ICU admission are risk factors for HAI. These findings emphasize the need for focused infection prevention and management to improve high-risk burn patient survival.

MRSA: diagnosis, screening and management

Staphylococcus aureus (S. aureus) is a common gram-positive bacterium that colonises human skin and mucous membranes​[1]​. It is usually a harmless member of the skin flora; however, infection can occur if there is a breach to the skin or mucosal barrier, followed by tissue invasion and damage​[2]​. While it frequently causes skin and soft tissue […]

The “Carpenter,” a substrate for green synthesis: Biosynthesis and antimicrobial potential

The frequent use of antibiotics has created favorable conditions for bacteria to develop resistance. Bacterial resistance is an issue for global health killing at least 1 million people worldwide annually. The quest for new and effective antimicrobials with activities against resistance bacteria demands immediate attention. The use of nanoparticles as antimicrobials alternatives to conventional antibiotics may have the potential to combat bacterial resistance. Silver nanoparticles, silver nanoparticles have captivated the interest of most researchers by virtue of their broad-range antimicrobial activity against bacteria due to their strong biocidal effect against microorganisms. Silver nanoparticles have been traditionally synthesized by physical chemical and biological process. However, biosynthesis of silver nanoparticles from wings of carpenter bees Xylocopa virginica, which is abundantly available in summer in the United States of America, is yet to be explored. Herein, we report the synthesis of silver nanoparticles using wing extract of carpenter bees X. virginica. Subsequently the biosynthesized nanoparticles were characterized by UV&amp;ndash;Visible absorption spectroscopy and scanning electron microscopy (SEM). Furthermore, the antimicrobial activity of the biosynthesized nanoparticles was investigated against two common Gram-negative and Gram-positive pathogenic bacteria viz Klebsiella pneumonia, Escherichia coli, Micrococcus luteus and Staphylococcus aureus using microdilution method. The results of this study indicate that biosynthesized silver nanoparticles from X. virginica wing extract showed an absorption band at 440 nm and SEM revealed spherical nanoparticles 20- 60 nm in size. Additionally, biosynthesizes silver nanoparticles from the wings of X. virginica exhibited antimicrobial activity against all the tested bacteria signifying their biomedical, pharmaceutical, and agricultural potential.

Sustainable Coating Based on Zwitterionic Functionalized Polyurushiol with Antifouling and Antibacterial Properties.

Zwitterionic polymer coatings facilitate the formation of hydration layers via electrostatic interactions on their surfaces and have demonstrated efficacy in preventing biofouling. They have emerged as a promising class of marine antifouling materials. However, designing multifunctional, environmentally friendly, and natural products-derived zwitterionic polymer coatings that simultaneously resist biofouling, inhibit protein adhesion, exhibit strong antibacterial properties, and reduce algal adhesion is a significant challenge. This study employed two diisocyanates as crosslinkers and natural urushiol and ethanolamine as raw materials. The coupling reaction of diisocyanates with hydroxyl groups was employed to synthesize urushiol-based precursors. Subsequently, sulfobetaine moieties were introduced into the urushiol-based precursors, developing two environmentally friendly and high-performance zwitterionic-functionalized polyurushiol antifouling coatings, denoted as HUDM-SB and IPUDM-SB. The sulfobetaine-functionalized polyurushiol coating exhibited significantly enhanced hydrophilicity, with the static water contact angle reduced to less than 60°, and demonstrated excellent resistance to protein adhesion. IPUDM-SB exhibited antibacterial efficacy up to 99.9% against common Gram-negative bacteria (E. coli and V. alginolyticus) and Gram-positive bacteria (S. aureus and Bacillus. sp.). HUDM-SB achieved antibacterial efficacy exceeding 95.0% against four bacterial species. Furthermore, the sulfobetaine moieties on the surfaces of the IPUDM-SB and HUDM-SB coatings effectively inhibited the growth and reproduction of algal cells by preventing microalgae adhesion. This zwitterionic-functionalized polyurushiol coating does not contain antifouling agents, making it a green, environmentally friendly, and high-performance biomaterial-based solution for marine antifouling.