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Objective:To analyze the application value of metagenomic next-generation sequencing (mNGS) in the detection of pathogenic bacteria in brain abscesses.Methods:The data of patients with brain abscess in Tianjin Huanhu Hospital from January 2019 to December 2021 were retrospectively analyzed. All patients underwent stereotaxic abscess puncture and drainage. According to the different methods of pathogen detection, they were divided into bacterial culture group (bacterial culture only) and mNGS group (bacterial culture with mNGS). The clinical symptoms, abscess site, bacterial culture and mNGS results, antibiotic application protocol and prognosis of the patients were analyzed. The bacterial detection results of the two groups were analyzed, and the antibiotic application and prognosis were compared. χ 2 test, exact probability method and Mann Whitney test were used to compare the difference between the two groups. Results:A total of 43 patients with brain abscess were enrolled, including 21 cases in bacterial culture group and 22 cases in mNGS group. The positive rate of bacteria culture group was 42.9% (9/21), the positive rate of bacteria culture group was 45.5% (10/22), and the positive rate of mNGS detection was 100% (22/22). Only 3 cases in the bacterial culture group could have a clear bacterial source, while 17 cases in the mNGS group could have a clear bacterial source according to the bacterial results, showing a significant statistical difference between the two groups (χ 2=19.69, P<0.001). The return time of bacterial culture was 7.0 (4.0,7.0) days, and the average return time of mNGS was 1.5 (1.5,1.5) days, the difference of bacterial return time between the two groups was statistically significant ( Z=0.00, P<0.001). The cost of antibiotic use in bacterial culture group was 24.00 (5.60,31.00) thousands yuan, and the cost of antibiotic use in mNGS group was 12.00 (2.10, 20.00) thousands yuan, and there was significant statistical difference between them ( Z=5.22, P=0.026). Conclusions:MNGS can quickly and accurately identify the types and sources of brain abscess pathogens, guide the clinical application of antibiotics more targeted, reduce the cost of antibiotic use, and is an effective method for the detection of brain abscess pathogenic bacteria.
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@#Abstract: Objective To investigate the distribution and drug resistance of pathogenic bacteria separated from ascites of patients in Children’s Hospital Affiliated to Zhengzhou University from 2015 to 2021, and to provide a basis for rational clinical antimicrobial agents. Methods Bacterial culture, bacterial identification and drug sensitivity analysis were performed on 1 058 non-duplicate ascites culture specimens from January 2015 to December 2021. The clinica1 and microbiologica1 data were ana1yzed by WHONET 5.6 and SAS 9.4 Results Of the 1 058 specimens, 586 (55.39%) were positive for pathogenic bacteria, with a total of 781 strains isolated. There was no significant trend of increase or decrease in the positivity rate over different years. Male children (63.99%) were more prevalent than female children. Appendicitis (59.22%) was the most common disease and Escherichia coli was the most common causative bacteria. Among neonates (≤28 d), the bacteria with the highest detection rate were Klebsiella pneumoniae (23.50%) and Enterococcus faecium (23.50%), while among children (>28 d), the highest detection rate was Escherichia coli (35.98%). Gram-negative bacteria accounted for 64.79% of the 781 strains, mainly Escherichia coli (38.28%), Klebsiella pneumoniae (8.58%), and Pseudomonas aeruginosa (5.89%); Gram-positive bacteria accounted for 29.45%, mainly Enterococcus faecium (8.58%), Streptococcus constellatus (2.69%), and Enterococcus avium (2.43%); fungi accounted for 1.66% and anaerobic bacteria accounted for 4.10%. The resistance rates of Escherichia coli to cefoperazone/sulbactam, piperacillin/tazobactam, imipenem and meropenem were 6.02%, 4.35%, 4.35%, and 3.68%, respectively. The resistance rates of Klebsiella pneumoniae to these drugs were 59.70%, 59.70%, 50.75% and 53.73% respectively. Linezolid-resistant strains of Enterococcus faecium were found. Conclusion Appendicitis is the most common abdominal infection in children, and the distribution of ascites pathogens varies with ages and diseases. The pathogenic bacteria are mainly Gram-negative bacteria, and the drug resistance of Klebsiella pneumoniae was more serious. It is particularly important to use antibiotics correctly and rationally to reduce the emergence of drug resistant bacteria.
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@#Abstract: Objective To investigate the epidemiological characteristics of pathogens causing bloodstream infection in hematology patients during treatment and to compare the effects of allogeneic hematopoietic stem cell transplantation (HSCT) on them, so as to provide evidence for the diagnosis and treatment of bloodstream infection. Methods A total of 292 cases with bloodstream infection in hematology wards of the PLA General Hospital were collected from 2017 to 2021, which were divided into HSCT group and N-HSCT group according to whether performed HSCT or not. The epidemiological characteristics and influence of pathogenic bacteria in blood stream infection were analyzed and compared between the two groups. Results A total of 362 strains of pathogenic bacteria were collected from 292 cases, including 106 strains in HSCT group (84 cases) and 256 strains in N-HSCT group (208 cases). Bloodstream infections were more common in acute myeloid leukemia (130/392, 44.52%), followed by non-Hodgkin's lymphoma (74/292, 25.34%). The rate of once bloodstream infection in HSCT group was higher than that in N-HSCT Group, but the rate of twice bloodstream infections in N-HSCT group was higher. Gram-negative Bacilli were the most common pathogens (56.08%), with Escherichia coli being absolutely dominant (109/362, 30.11%), followed by Klebsiella pneumoniae (39/362, 10.77%). Coagulase-negative staphylococci (CoNS) (107/362, 29.56%) were the most common Gram-positive cocci. The detection rate of fungi in HSCT group (10/106, 9.43%) was significantly higher than that in N-HSCT Group (3.52%). The drug resistance rate of the common pathogenic bacteria was at a high level, and there was a certain proportion of multi-drug resistant strains (except for Pseudomonas aeruginosa). The resistance rates of CoNS to penicillin, gentamicin, moxifloxacin, clindamycin and rifampicin in HSCT group were higher than those in N-HSCT Group. The resistance rate of Escherichia coli to piperacillin/tazobactam, cephalosporins and etapenem in HSCT group was significantly higher than that in N-HSCT group. Conclusions The pathogens of blood stream infection in hematology patients are complicated and various. It is difficult for clinical diagnosis and treatment to detect multiple infections and multiple pathogens. HSCT patients have a higher risk of fungal bloodstream infection and more multi-drug resistant strains detected. Therefore, the identification of bloodstream infection and multi-drug resistant strains associated with HSCT patients should prompt surveillance.
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@#Abstract: Objective To analyze the distribution and drug resistance of pathogenic bacteria in blood culture specimens of patients with bloodstream infections before and after COVID-19 (2018-2019 and 2020-2021), and to provide scientific basis and reference for rational treatment and effective control of bloodstream infections in the post-epidemic period. Methods Blood culture specimens were collected from patients in Zhongnan Hospital of Wuhan University in the two years before and after the COVID-19 outbreak (2018-2021). The Automated Blood Culture Systems were used to perform blood culture on blood specimens sent for clinical inspection, and the Vitek MS automatic bacterial identification mass spectrometer was used for strain identification and the Vitek 2 automatic bacterial drug susceptibility analyzer was used for drug susceptibility testing and drug resistance analysis. Results Blood culture specimens were performed on 28 736 patients with suspected bloodstream infection submitted for inspection from January 2018 to December 2019, and a total of 2 181 strains of pathogenic bacteria were detected after removing duplicate strains, with a positive rate of 7.69%, including 1 046 strains of Gram-negative bacteria, accounting for 47.96%. From January 2020 to December 2021, blood culture specimens from 26 083 patients with suspected bloodstream infection were submitted for inspection, and a total of 2 111 strains of pathogenic bacteria were detected after excluding duplicate strains, with a positive rate of 8.09%, including 1 000 strains of Gram-negative bacteria accounted for 47.37%. The drug resistance of Klebsiella pneumoniae was relatively serious, and the sensitivity rate to ertapenem, polymyxin B and tigecycline was more than 90%. The main non-fermentative bacteria Acinetobacter baumannii was more than 50% sensitive to piperacillin/tazobactam, amikacin and polymyxin B. The sensitivity rates of Pseudomonas aeruginosa to piperacillin/tazobactam, ceftazidime, cefepime, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, piperacillin and meropenem were more than 50%. Conclusions In the two years before and after COVID-19, there are many types of pathogenic bacteria in bloodstream infection, but the distribution do not differ significantly. The pathogens of bloodstream infection are mainly distributed in ICU, hepatobiliary research institute, and nephrology department. Among them, Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii are the main ones, and different pathogens showed great differences in drug resistance.
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@#Abstract: Objective To analyze the distribution characteristics of the main pathogens of HIV/AIDS patients with wound infections and provide basis for clinical diagnosis and treatment. Methods The clinical data of 294 patients with positive secretions or pus specimens from 2016 to 2020 were analyzed retrospectively. Results A total of 357 strains of pathogenic bacteria were isolated from 294 cases, of which 123 strains of Gram-negative bacilli (G-b), accounting for 34.5%, were mainly Escherichia coli (15.4%), Klebsiella pneumoniae (3.9%), and Pseudomonas aeruginosa (3.6%); Gram-positive bacilli (G+b) 14 strains, accounting for 3.9%; 108 Gram-positive cocci (G+c), accounting for 30.3%, of which 44 strains were coagulase-positive Staphylococcus aureus (12.3%), Coagulase-negative staphylococci were mainly Staphylococcus epidermidis (4.2%) and Staphylococcus hemolyticus (2.8%); 37 strains of fungi, accounting for 10.4%, were mainly Candida albicans (5.9%); 75 strains of Mycobacterium, accounting for 21.0%, including 41 strains of Mycobacterium tuberculosis (11.5%) and 34 strains of non-tuberculosis mycobacteria (9.5%). 52 of the 294 HIV/AIDS patients had mixed infections, accounting for 17.7%. There was significant difference in the distribution of G+c, G-b, mycobacteria and mixed infection among different specimen sources (P<0.05), and there was significant difference in the distribution of mycobacteria among different CD4+T lymphocyte counts (P<0.05). There was significant difference in the level of CD4+T lymphocytes between patients of different ages (P<0.05), and there was significant difference in the level of CD4+T lymphocytes from postoperative incision and other parts (P<0.05). Conclusions Patients with HIV/AIDS are prone to combined wound infections with various pathogenic bacteria. We should strengthen the research on wound infection in HIV/AIDS patients, and timely send patients with a low number of CD4+T lymphocytes for secretion or pus culture, so as to carry out targeted treatment and improve the prognosis of patients.
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Aims@#The current study was aimed to evaluate the antibacterial activity of biogenic synthesized golden nanoparticles from Sophora flavescens Aiton roots aqueous extract against multidrug-resistant (MDR) clinical bacterial isolates.@*Methodology and results@#The green synthesis of gold nanoparticles (AuNPs) was accomplished using S. flavescens roots aqueous extract and examined using many accepted techniques. The antibacterial activity of S. flavescens extract and the aqueous AuNPs at concentrations (7% and 9%) ppm were investigated against two clinical MDR bacteria, including Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa). The findings demonstrate inhibitory activity against the selected MDR bacterial isolates for the aqueous extract of S. flavescens and the aqueous AuNPs noted by the significant decrease in the number of bacteria after treatment with highly significant differences (P≤0.01) compared to the untreated control.@*Conclusion, significance and impact of study@#Sophora flavescens root extracts and their biosynthesized AuNPs with antibacterial activity may find broad applications in fighting MDR pathogenic bacteria and therapeutic manufacturing.
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Anti-Bacterial Agents , Sophora flavescensABSTRACT
OBJECTIVE@#To investigate the distribution and drug sensitivity of pathogenic bacteria isolated from patients in hematology department, in order to provide evidence for rational use of antibiotics in clinic.@*METHODS@#The distribution of pathogenic bacteria and drug sensitivity data of patients in the hematology department of The First Affiliated Hospital of Nanjing Medical University from 2015 to 2020 were retrospectively analyzed, and the pathogens isolated from different specimen types were compared.@*RESULTS@#A total of 2 029 strains of pathogenic bacteria were isolated from 1 501 patients in the hematology department from 2015 to 2020, and 62.2% of which were Gram-negative bacilli, mainly Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii. Gram-positive coccus accounted for 18.8%, mainly Coagulase-negative staphylococcus (CoNS) and Staphylococcus aureus. Fungi (17.4%) were mainly candida. The 2 029 strains were mainly isolated from respiratory tract (35.1%), blood (31.8%) and urine (19.2%) specimens. Gram-negative bacilli were the main pathogenic bacteria in different specimen types (>60%). K. pneumoniae, S. maltophilia and A. baumannii were the most common pathogens in respiratory specimens, E. coli, CoNS, K. pneumoniae and P. aeruginosa were common in blood samples, and E. coli and Enterococcus were most common in urine samples. Enterobacteriaceae had the highest susceptibility to amikacin and carbapenems (>90.0%), followed by piperacillin/tazobactam. P. aeruginosa strains had high sensitivity to antibiotics except aztreonam (<50.0%). The susceptibility of A. baumannii to multiple antibiotics was less than 70.0%. The antimicrobial resistance rates of E. coli and K. pneumoniae in respiratory tract specimens were higher than those in blood specimens and urine specimens.@*CONCLUSION@#Gram-negative bacilli are the main pathogenic bacteria isolated from patients in hematology department. The distribution of pathogens is different in different types of specimens, and the sensitivity of each strain to antibiotics is different. The rational use of antibiotics should be based on different parts of infection to prevent the occurrence of drug resistance.
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Humans , Escherichia coli , Retrospective Studies , Bacteria , Anti-Bacterial Agents/therapeutic use , Gram-Negative Bacteria , Drug Resistance , Pseudomonas aeruginosa , HematologyABSTRACT
Objective To analyze the epidemiological characteristics and drug resistance of pathogenic bacteria in 276 hospitalized children with lower respiratory tract infection to facilitate prevention and treatment. Methods Among of 276 hospitalized children with lower respiratory tract infection from January 2019 to December 2021 were analyzed. Data on the distribution of pathogenic bacteria were collected and analyzed. At the same time, the information on drug resistance was collected, and the potential relationship between pathogen distribution and drug resistance was briefly analyzed and discussed. Results A total of 532 strains of pathogenic bacteria were detected in the blood samples from 276 patients in this study. There were 207 strains of Gram-positive bacteria, including 104 strains of Staphylococcus aureus, 96 strains of Staphylococcus epidermidis and 7 strains of others. Gram negative bacteria (325 strains) were 172 strains of Klebsiella and 153 strains of Escherichia coli. The distribution of pathogenic bacteria in different gender and age groups (under 5 years old, 5-10 years old, and over 10 -14 years old) was calculated separately. The results showed that the distribution of pathogenic bacteria in female children under 5 years old (n=49 cases) was different from the total population: the infection of Gram-positive bacteria was higher than that of Gram-negative bacteria, and the proportion of Staphylococcus epidermidis was the highest (P<0.05). The distribution characteristics of children of other ages and sexes were consistent with the total distribution characteristics. The resistance rate of Gram-positive bacteria to penicillin, erythromycin and clarithromycin was high, while the resistance rate of Gram-negative bacteria to ampicillin, cefazolin and cefuroxime was high. The distribution characteristics were the same in children of different sex and age. Conclusion The pathogenic bacteria in children with lower respiratory tract infection in pediatric ward are mainly Gram-negative bacteria, and the main pathogenic bacteria have a high resistance rate to common drugs. The distribution of pathogenic bacteria in female children under 5 years old is unique: the infection of Gram-positive bacteria is higher than that of Gram-negative bacteria, and the proportion of Staphylococcus epidermidis is the highest, which deserves attention. The clinical drug sensitivity test can be used as an important reference for the treatment of drugs to guide the rational selection of antibiotics.
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Objective:To analyze the distribution of pathogenic bacteria in bile culture in patients with common bile duct stones and biliary tract infections, in order to guide clinical optimization of antibiotics application.Methods:From March 30, 2017 to December 31, 2021, at Affiliated Hospital of Qingdao University, 753 patients with common bile duct stones and biliary tract infections and received endoscopic retrograde cholangiopancreatography were selected. Bile samples were obtained for bacterial culture, strain type identification and drug sensitivity test in order to analyze bile pathogenic bacteria distribution, change trend and drug resistance. Chi-square test was used for statistical analysis.Results:From 2017 to 2021, the total positive rate of bile culture in 753 patients with choledocholithiasis complicated with biliary tract infection was 90.17% (679/753). From 2017 to 2021, the positive rates of bile culture were 82.05% (64/78), 88.81% (119/134), 88.03% (125/142), 93.87% (199/212), and 91.98% (172/187), respectively, and the difference was statistically significant ( χ2=10.78, P=0.029). The positive rate of bile culture in 2017 was lower than those in 2020 and 2021, and the differences were statistically significant ( χ2=9.43 and 5.57, P=0.002 and 0.018). There were no significant differences in the positive rates of bile culture among the other years (all P>0.05). A total of 1 033 pathogenic bacteria were detected in the 679 bile specimens with positive bile culture results. Among which the total proportion of Gram-negative bacilli was 57.02% (589/1 033), and from 2017 to 2021 the proportions were 66.38% (77/116), 66.47% (111/167), 59.43% (104/175), 54.75% (173/316), and 47.88% (124/259), respectively. The total proportion of Gram-positive cocci was 41.05% (424/1 033), and from 2017 to 2021 the proportions were 31.90% (37/116), 31.74% (53/167), 38.86% (68/175), 44.30% (140/316), and 48.65% (126/259), respectively. The total proportion of fungus was 1.94% (20/1 033), and from 2017 to 2021 the proportions were 1.72% (2/116), 1.80% (3/167), 1.71% (3/175), 0.95% (3/316), and 3.47% (9/259), respectively. From 2017 to 2021, the proportion of Gram-negative bacilli gradually decreased, while the proportion of Gram-positive cocci gradually increased, and the differences were statistically significant ( χ2=20.14 and 17.91, P<0.001 and =0.001). From 2017 to 2021, the change in the proportion of fungus was not statistically significant ( P>0.05). The main Gram-negative bacilli in the bile culture were Escherichia coli (31.36%, 324/1 033) and Klebsiella pneumoniae (12.68%, 131/1 033); the main Gram-positive cocci were Enterococcus faecalis (14.04%, 145/1 033) and Streptococcus salivarius (4.36%, 45/1 033). From 2017 to 2021, the proportions of Escherichia coli were 39.66% (46/116), 38.92% (65/167), 33.14% (58/175), 28.48% (90/316), and 25.10% (65/259), respectively, with gradual decrease and the difference was statistically significant ( χ2=14.34, P=0.006). From 2017 to 2021 the detection rates of extended-spectrum β-lactamase (ESBL) in Escherichia coli and Klebsiella pneumoniae were 30.43% (14/46), 26.15% (17/65), 29.31% (17/58), 38.89% (35/90), 40.00% (26/65), and 4/15, 20.00% (5/25), 20% (5/25), 24.32% (9/37), and 31.03% (9/29), and there were no significant differences in the detection rates of ESBL between different years (both P>0.05). Conclusions:From 2017 to 2021, the positive rate of bile culture in patients with choledocholithiasis complicated with biliary tract infection showed an overall increasing trend. Gram-negative bacilli were still dominated in bile pathogenic bacteria, while the proportion of Gram-positive cocci remarkably increased, and the bile bacterial spectrum significantly changed. Clinicians should adjust the antibiotic dosing regimens according to the variation of bacterial spectrum and drug resistance.
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Objective:To analyze the distribution and drug resistance of pathogenic bacteria in skin and soft tissue infections.Methods:The lesion samples were collected from patients with skin and soft tissue infections in the First Affiliated Hospital of Hainan Medical College from January 2012 to September 2021, and the distribution of pathogenic bacteria and their drug resistance were analyzed. The data were analyzed with SPSS 23.0 statistical software.Results:A total of 692 strains of pathogenic bacteria were isolated from 1 121 patients.There were 372 strains of Gram-negative bacteria (53.76%), mainly Pseudomonas aeruginosa ( n=92, 13.29%), Klebsiella pneumoniae ( n=55, 7.95%) and Enterobacter cloacae ( n=38, 5.49%); 276 strains of gram-positive bacteria (39.88%), mainly Staphylococcus aureus ( n=140, 20.23%), Streptococcus pyogenes ( n=38, 5.49%) and Enterococcus faecalis ( n=27, 3.90%); and 44 strains of fungi (6.36%), mainly Candida albicans ( n=19, 2.75%) and Candida tropicalis ( n=7, 1.01%). Staphylococcus aureus had a high resistance rate to penicillin G (53.57%), and Streptococcus pyogenes had a high resistance rate to tetracycline (89.47%). The resistance rate of Pseudomonas aeruginosa to furantoin was high (29.35%). The resistance rate of Klebsiella pneumoniae to ceftriaxone (38.18%) and cefzolin (36.36%) was high. The detection rate of Klebsiella pneumoniae in patients with community-acquired infection was higher than that in patients with hospital-acquired infection ( χ2=5.272, P=0.022). Conclusion:Gram-negative bacteria are the main pathogenic bacteria of skin and soft tissue infections in this area. Antibiotics should be used rationally according to the distribution of main pathogenic bacteria locally and the results of drug sensitivity.
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Abstract Potable water supply and sanitization in rural areas in developing countries are still inadequate. The main risk associated with unsafe drinking water is the infection with pathogenic microorganisms. Objective: In this study, we investigate the bacterial diversity and the potentially pathogenic bacteria in water samples from diffe rent points of distribution in three rural villages from the Andean region of Colombia. Methods: Illumina libraries for water samples were prepared and sequenced using 300 bp paired-end MiSeq protocol, the bioinformatic analyses were performed with Mothur pipeline and the phyloseq package in Rstudio. Results: The mi crobial community composition showed statistically significant differences according to the village and the sample origin. Alpha, Beta, and Gammaproteobacteria were the dominant class detected in all water samples. The most relevant pathogenic genera detected in the surface were Legionella, Mycobacterium, Yersinia, Burkholderia, and Rickettsia. In the tap water samples, potential pathogens like Streptococcus, Staphylococcus, Corynebacterium, Nocardia, and Escherichia/Shige lla were detected.
Resumen El suministro y potabilización del agua de consumo humano en las zonas rurales de los países en vías de desarrollo sigue siendo limitado. El principal riesgo asociado con el uso de agua no potable es la infección con microorganismos patógenos. Objetivo: En este estudio se investigó la diversidad bacteriana y la presencia de bacterias potencialmente patógenas en muestras de agua de diferentes puntos de distribución en tres asentamientos rurales de la región andina de Colombia. Métodos: Se prepararon y secuenciaron bibliotecas de amplicones (rDNA 16S) para muestras de agua utilizando la plataforma Illumina MiSeq con lecturas pareadas de 300 bases. Los análisis bioinformáticos se realizaron con el programa Mothur y el paquete estadístico Phyloseq en Rstudio. Resultados: La composición de la comunidad microbiana mostró diferencias estadísticamente significativas según el sitio y el origen de la muestra. Alfa, Beta y Gammaproteobac terias fueron las clase dominantes detectadas en todas las muestras de agua. Los géneros patógenos más relevantes detectados fueron Legionella, Mycobacterium, Yersinia, Burkholderia y Rickettsia. En las muestras de agua del grifo se detectaron patógenos potenciales como Streptococcus, Staphylococcus, Corynebacterium, Nocardia y Escherichia /Shigella.
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Drug discovery aimed at the methodical extermination of life-threatening bacterial infection, especially considering the emergence of multi-drug resistance of pathogenic bacteria has remained a challenge for medicinal inorganic chemistry. In this article, the mixed ligand complexes of Cu (II), Co (II), and Ni (II) containing heterocyclic ligands were synthesized and characterized by IR, LC-MS, UV, and TG-DTA. Complexes are screened for Anti-microbial activity against human pathogenic bacteria.
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Aims@#Lactic acid bacteria (LAB) biofilms constitute one of the most remarkable breakthroughs in the field of food biopreservatives and can be employed to prevent foodborne disease. The purposes of this study were to investigate the efficacy of inhibitory LAB biofilms against foodborne pathogens and evaluate their tolerance to acidic pH and bile salts, as well as their physicochemical properties.@*Methodology and results@#Four strains of Lactobacillus brevis biofilms isolated from kimchi showed antipathogenic activity to the bacteria Staphylococcus aureus FNCC 0049 and Escherichia coli FNCC 0091. These biofilms were also tolerant to pH 2.5, 0.3% bile salt and strong adhesion. Two of the four L. brevis biofilms (L. brevis biofilm KA2 and KB1) produced the highest inhibitory activity against both pathogenic bacterial indicators, tolerance to acidic pH and bile salts, and the strongest adhesion. In addition, based on Scanning Electron Microscope-Energy Dispersion X-ray Spectroscopy (SEM-EDS) analysis, both biofilm strains had a smooth surface texture; the cell morphology was rod-shaped and consisted of several elements such as carbon, oxygen and nitrogen, which was built up of extracellular polymeric substances (EPS).@*Conclusion, significance and impact of study@#The presence of EPS as a constituent of LAB biofilms influenced their survival abilities in an acidic pH and bile salt environment. As a result, the characteristics of L. brevis biofilm KA2 and KB1 made them excellent candidates for use as antimicrobial packaging systems in food biopreservative applications.
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Levilactobacillus brevis , Lactobacillales , Foodborne DiseasesABSTRACT
@#Abstract： Objective To investigate the distribution and antimicrobial resistance profile of the bacterial strains isolated from blood cultures in neonatal septicemia children of Neonatology Department, the First People's Hospital of Chuzhou during Jan. 2017-Dec. 2021, in order to guide clinical rational drug use. Methods The distribution and the results of antimicrobial susceptibility tests and characteristics of the pathogenic bacteria isolated from blood culture samples in neonatal septicemia children in the First Hospital of Chuzhou from Jan. 2017 to Dec. 2021 were retrospectively analyzed. The results were analyzed with WHONET 5.6 software, according to the Clinical and Laboratory Standards Institute (CLSI) 2021 breakpoints. Results A total of 189 strains were isolated from the 4 538 sample of blood cultures, the positive rate was 4.2%, including 59(31.2%) Gram-negative bacterial strains, 130 (68.8%) Gram-positive bacterial strains. The most frequently isolates were coagulase-negative staphylococci（64.0%), Serratia liquefaciens (15.9%), Escherichia coli (3.2%), Acinetobacter lwoffii (2.6%) and Delftia acidovorans (2.6%). The prevalence of methicillin-resistant isolates was 81.8%(99/121) in coagulase-negative Staphylococci and 25.0%（1/4） in Staphylococcus aureus. No staphylococcal strains were found resistant to vancomycin, quinupristin-dalfopristin or linezolid. The sensitivity of the antibacterial drug monitored by Serratia liquefaciens was 100.0%.Conclusions Gram-positive bacterial are the main pathogen of neonatal septicemia, and is highly resistant to the common antibacterial drugs. The clinical should choose antibacterial agents reasonably according to drug sensitivity.
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@#Abstract: Objective To investigate the distribution and drug resistance characteristics of pathogenic bacteria in patients with neutropenic acute leukemia (AL) and bloodstream infections (BSI). Methods The clinical data of 258 neutropenic acute leukemia patients with bloodstream infections, who admitted to Shengjing Hospital of China Medical University from January 2016 to December 2021, were collected and analyzed for pathogenic bacteria and drug resistance. Results A total of 268 strains of pathogenic bacteria were isolated from 258 patients, including 180 strains of gram-negative bacteria (67.16%), 61 strains of gram-positive bacteria (22.76%), and 27 strains of fungi (10.07%). Gram-negative bacteria were mainly Klebsiella pneumoniae (53/268, 19.78%), Escherichia coli (49/268, 18.28%) and Pseudomonas aeruginosa (41/268, 15.30%). Gram-positive bacteria were mainly coagulase negative Staphylococcus (31/268, 11.57%) and Staphylococcus aureus(17/268, 6.34%). The main fungi were Candida tropicalis (25/268, 9.33%). Escherichia coli (33/268, 12.31%) was the most common pathogen isolated from acute myeloid leukemia (AML), followed by Pseudomonas aeruginosa (25/268, 9.33%), coagulase-negative Staphylococcus (18/268, 6.72%) and Candida tropicalis (18/268, 6.72%). Klebsiella pneumoniae (35/268, 13.06%) was the most common pathogen isolated from acute lymphoblastic leukemia (ALL),followed by Pseudomonas aeruginosa (15/268, 5.60%) and Escherichia coli (14/268, 5.22%). The resistance of Gram-negative bacteria to piperacillin/tazobactam, cefoperazone/sulbactam, imipenem, meropenem, ertapenem, amikacin, cefoxitin, amoxicillin/clavulanic acid was low. Gram-positive bacteria were sensitive to linezolid and vancomycin. Candida was sensitive to flucytosine, amphotericin B and itraconazole. Conclusions In patients with granulosa after AL chemotherapy combined with BSI, the pathogenic bacteria isolated from AML are diverse, and the pathogenic bacteria isolated from ALL are mainly gram-negative bacteria. Pathogenic bacteria have different degrees of drug resistance to commonly used antibacterial drugs, so it is important to strengthen the monitoring of the distribution of pathogenic bacteria and the change of drug resistance and rational use of antibacterial drugs to minimize the death of patients.
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Objective:To investigate the distribution, drug resistance and clinical significance of bacteria and fungi in pancreatic juice of patients with severe acute pancreatitis (SAP).Methods:Data of patients with severe acute pancreatitis receiving ERCP treatment and pancreatic juice bacterial culture at Department of Hepatobiliary Surgery, General Hospital of Ningxia Medical University from Jan 2019 to Jun 2020 were retrospectively analyzed.Results:A total of 97 patients were included. Pathogens were isolated from 46 (47.42%) pancreatic juice samples, with 71 strains including 43 (60.56%) gram negative bacteria, 26 (36.62%) gram positive bacteria, and 2 (2.82%) fungi. The C-reactive protein (CRP), D-dimer and Balthazar CT Score in the culture positive group were higher than those in the culture negative group ( P < 0.05). The incidence of complications and pancreatic infection in the culture positive group was also significantly higher ( P < 0.05). Conclusions:The positive rate of pancreatic juice bacterial culture in the early stage of severe acute pancreatitis is high, in which Gram-negative bacteria are most common, followed by Gram-positive bacteria and fungi. The presence of pathogens in pancreatic juice predicts ensuing infections.
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Objective:To investigate the distribution and antimicrobial resistance patterns of common pathogens in children with urinary tract infections in a single center in Shanghai, and to provide basis for the selection of empirical antibiotics in the clinical practice.Methods:The clinical data, urine culture and drug sensitivity tests results of children with urinary tract infections between 0 to 14 years admitted to the Children′s Hospital of Fudan University from January 2016 to December 2019 were retrospectively analyzed. According to the time of onset and the complicated factors, the patients were divided into different groups. The distributions and antimicrobial resistance patterns of common pathogens were compared among the groups. The chi-square test was used for statistical analysis.Results:Among the 1 832 children, 1 042 cases had positive urine culture, with the culture positive rate of 56.9%. The top five pathogens detected were Escherichia coli (375 strains, 36.0%), Enterococcus faecium (164 strains, 15.7%), Klebsiella pneumoniae (133 strains, 12.8%), Enterococcus faecalis (95 strains, 9.1%) and Pseudomonas aeruginosa (44 strains, 4.2%). The annual detection rates of gram-negative bacteria (65.3% to 72.9%) were always higher than those of gram-positive bacteria (22.6% to 30.1%). The distributions of pathogens among the years were not significantly different ( χ2 =27.79, P=0.146). In patients with complicated urinary tract infections, the detection rates of Pseudomonas aeruginosa (5.8%(40/688) vs 1.1%(4/354)) and fungi (6.5%(45/688) vs 1.7%(6/354)) were significantly higher than those in patients with simple urinary tract infections ( χ2=12.68 and 11.79, respectively, both P<0.050). Both of Escherichia coli and Klebsiella pneumoniae had the highest resistance rates to ampicillin, which were 87.2%(301/345) and 87.1%(115/132), respectively. The resistance rates of Escherichia coli to amikacin, nitrofurantoin, fosfomycin, cefmetazole, piperacillin/tazobactam, ertapenem, imipenem and meropenem were 1.4%(5/345), 6.1%(21/345), 6.1%(21/345), 8.3%(11/132), 11.6%(40/345), 6.4%(22/345), 4.6%(16/345) and 4.6%(16/345), respectively. The resistance rates of Klebsiella pneumoniae to these drugs were 6.1%(8/132), 37.9%(50/132), 15.2%(20/132), 23.2%(13/56), 26.5%(35/132), 23.5%(31/132), 17.4%(23/132) and 16.7%(22/132), respectively, which were all higher than those of Escherichia coli, and the differences were all statistically significant ( χ2=6.02, 76.17, 9.99, 7.94, 16.04, 28.29, 20.79 and 18.84, respectively, all P<0.050). The resistance rates of Pseudomonas aeruginosa to cefoperazone/sulbactam, piperacillin/tazobactam and ceftazidime were 6.8%(3/44), 4.5%(2/44) and 2.3%(1/44), respectively, while those to carbapenems, amikacin and ciprofloxacin were all 0(0/44). The resistance rate of Enterococcus faecium to ampicillin was 96.8%(153/158), while that of Enterococcus faecalis was 9.1%(8/88). There was no Enterococcus strain resistant to vancomycin, teicoplanin or linezolid. When dynamically comparing the trends of the antimicrobial resistance from 2016 to 2019, the resistance rates of Escherichia coli and Klebsiella pneumoniae to β-lactams (including carbapenems) antimicrobial agents had shown a downward trend. Conclusions:Gram-negative bacteria are still the main pathogens of urinary tract infections in children, with a downward trend of drug resistance rates to β-lactams (including carbapenems) antimicrobial agents.
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Objective:To study the clinical features and high-risk factors of early-onset sepsis (EOS) in extremely preterm and super preterm infants.Methods:Retrospective study.Clinical data of extremely preterm and super preterm infants with the gestational age < 32 weeks were obtained from the clinical database of breast milk quality improvement registration in the Woman′s Hospital of Nanjing Medical University between January 2019 and December 2019.EOS cases were enrolled in the EOS group, and the remaining were enrolled in the control group.Risk factors for EOS, distribution of pathogenic bacteria, clinical features, complications, and outcomes between groups were analyzed.Measurement data were compared between the independent sample t-test.Counting data between groups were compared by the Chi- square test, corrected Chi- square test or Fisher′ s exact test.Multivariable Logistic regression model was used to analyze the risk factors of EOS in extremely and super preterm infants. Results:A total of 347 eligible neonates were recruited, including 22 neonates with EOS and 325 neonates without EOS.The incidence rate of EOS was 6.3%.Multivariate Logistic regression analysis showed that cesarean delivery was the protective factor for EOS ( OR=0.277, 95% CI: 0.091-0.847); while maternal prenatal infection ( OR=2.750, 95% CI: 1.053-2.908), fetid amniotic fluid ( OR=3.878, 95% CI: 1.344-11.187), chorioamnionitis ( OR=4.363, 95% CI: 1.552-12.236) and intubation ( OR=3.883, 95% CI: 1.133-13.306) were risk factors for EOS.A total of 22 strains of pathogenic bacteria were cultured in the EOS group, including 14 strains (63.6%) of Gram-positive bacteria, 7 strains (31.8%) of Gram-negative bacteria and 1 strain (4.6%) of fungus.The acute respiratory distress syndrome (54.5%), poor peripheral circulation perfusion (54.5%), mental depression (50.0%), and procalcitonin>0.5 mg/L (40.9%) were the main clinical features of EOS.Compared with the control group, extremely preterm and super preterm infants with EOS had a significantly higher rate of septic shock, disseminated intravascular coagulation, severe intraventricular hemorrhage (≥Ⅲ), acute respiratory distress syndrome (ARDS), and bronchopulmonary dysplasia( χ2=36.696, 33.255, 13.534, 95.455 and 3.886, respectively; all P<0.05). Conclusions:Maternal perinatal infection, odor amniotic fluid, chorioamnionitis and delivery room tracheal intubation are high-risk factors for preterm and super preterm infants with EOS, which can be prevented by cesarean section.Gram-positive cocci are the main pathogenic bacteria of EOS.ARDS and poor peripheral circulation perfusion are the main clinical manifestations of EOS, which increase the occurrence of severe intracranial hemorrhage and other complications.
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Aims@#Due to the growing number of media reports claiming that books contain germs, it is crucial to look into the possibility that contagious diseases could spread through libraries. The aim of the study was to identify bacteria from various fomites in four Jordanian university libraries and to assess the antibacterial resistance pattern of isolates.@*Methodology and results@#In this study, swab samples were taken from different fomites of four Jordanian university libraries. Samples were then cultivated on nutrient agar and incubated aerobically at 37 °C for 48 h. To identify different types of isolated bacteria, biochemical and conventional biochemical tests were applied using the qualitative RapIDTM One System with the help of ERICTM software to identify the bacterial isolates at the species level. Identified bacterial species, including Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus epidermis, S. aureus, Salmonella choleraesuis, Bacillus subtilis and Citrobacter freundii were isolated from different library fomites. Seventy-one bacterial isolates from University A were observed to be multidrug-resistant (MDR) (S. sonnei and S. choleraesuis). This MDR pattern is alarming as those isolates were found in a public environment and that imposes a direct threat on library users, staff and visitors.@*Conclusion, significance and impact of study@#University libraries' fomites carry live bacterial pathogens, which can contaminate users' hands and serve as an indirect route for spreading antibiotic resistance and microbial illnesses. While more research is required, considering hand hygiene improvement would be the simplest infection control technique at libraries. Additionally, proactive measures should be taken to track the prevalence of harmful microorganisms in these settings and their effects on employees' and the public's health.
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Drug Resistance, Bacterial , Communicable DiseasesABSTRACT
Based on the idea of multi-target drug design, taking p-aminosalicylic acid (PAS) as the parent nucleus, the unreported target molecules TM1 and TM2 were designed with PAS, isonicotinic acid and fluoroquinolone as three structural units conjugated by different linkers. Sixteen target molecules were synthesized by multi-step reaction, and their activities against Mycobacterium tuberculosis and human pathogenic bacteria were evaluated. The results showed that the anti-tuberculosis activity of TM2a was stronger than those of the assayed fluoroquinolones, while TM1a was comparable to that of clinafloxacin, the most active compound of the positive control fluoroquinolones; TM1a showed the strongest inhibitory activity to all almost tested strains, TM1b and TM2a showed very strong inhibitory activity to most strains, and TM1h/2h had strong inhibitory activity to some strains; The inhibitory activities of TM1a/1h on Staphylococcus aureus ATCC14125 are much stronger than those of fluoroquinolones, which eminently deserves further study. The hemolysis test results showed that the highly active molecules TM1a and TM2a exhibited relative safety below the concentrations of 8 and 32 μg·mL-1, respectively. In this study, a new hybrid molecule of three molecular pharmacophores with PAS as the parent nucleus was synthesized for the first time, and some of which have highly strong antibacterial activity, which provides a new idea for the research and development of antibiotics.