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1.
Braz. j. biol ; 84: e249664, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1345558

ABSTRACT

Abstract The impact of antibiotics on growth, cocoon production was assessed in addition to isolation and characterization of bacteria associated with silkworm gut of infected larvae. Larval rearing was maintained at recommended conditions of temperature and humidity. Silkworm larvae showing abnormal symptoms were collected from the control group and dissected for gut collection. Bacteria were isolated from the gut content by spreading on agar plates and incubated at 37 °C for 48 hrs. Bacterial identification and phylogenetic analysis were carried out by 16S rRNA gene sequencing. The isolated bacteria were subjected to antimicrobial susceptibility test (disc diffusion methods) by using Penicillin (10 µg/mL), Tetracycline (30 µg/mL), Amoxicillin (25 µg/mL), Ampicillin (10 µg/mL), and Erythromycin (15 µg/mL). All isolated strains showed positive results for the catalase test. We isolated and identified bacterial strains (n = 06) from the gut of healthy and diseased silkworm larvae. Based on the 16S rRNA gene sequence, isolated bacteria showed close relation with Serratia, Bacillus, and Pseudomonas spp. Notably, 83.3% of strains were resistant to Penicillin, Tetracycline, Amoxicillin, Ampicillin, and Erythromycin but 16.6% showed antibiotic susceptibility to the above-mentioned commonly used antibiotics. Silkworm larvae fed on penicillin-treated leaves showed significant improvement in larval weight, larval length, and cocoon production. Significantly higher larval weight (6.88g), larval length (5.84cm), and cocoon weight (1.33g) were recorded for larvae fed on leaves treated with penicillin as compared to other antibiotics. Isolated bacterial strains showed close relation with Serratia spp., Bacillus spp. and Pseudomonas spp.


Resumo O impacto dos antibióticos no crescimento e na produção do casulo foi avaliado, além do isolamento e caracterização das bactérias associadas ao intestino de larvas infectadas do bicho-da-seda. A criação das larvas foi mantida nas condições recomendadas de temperatura e umidade. As larvas do bicho-da-seda com sintomas anormais foram coletadas do grupo controle e dissecadas para coleta do intestino. As bactérias foram isoladas do conteúdo intestinal por espalhamento em placas de ágar e incubadas a 37° C durante 48 horas. A identificação bacteriana e a análise filogenética foram realizadas pelo sequenciamento do gene 16S rRNA. As bactérias isoladas foram submetidas a teste de sensibilidade antimicrobiana (métodos de difusão em disco) com penicilina (10 µg / mL), tetraciclina (30 µg / mL), amoxicilina (25 µg / mL), ampicilina (10 µg / mL) e eritromicina (15 µg / mL). Todas as cepas isoladas apresentaram resultados positivos para o teste da catalase. Isolamos e identificamos cepas bacterianas (n = 06) do intestino de larvas de bicho-da-seda saudáveis e doentes. Com base na sequência do gene 16S rRNA, as bactérias isoladas mostraram estreita relação com Serratia, Bacillus e Pseudomonas spp. Notavelmente, 83,3% das cepas eram resistentes a penicilina, tetraciclina, amoxicilina, ampicilina e eritromicina, mas 16,6% mostraram suscetibilidade aos antibióticos comumente usados mencionados acima. As larvas do bicho-da-seda alimentadas com folhas tratadas com penicilina apresentaram melhora significativa no peso larval, comprimento larval e produção de casulo. Peso larval significativamente maior (6,88g), comprimento larval (5,84cm) e peso do casulo (1,33g) foram registrados para larvas alimentadas com folhas tratadas com penicilina, em comparação com outros antibióticos. Cepas bacterianas isoladas mostraram estreita relação com Serratia spp., Bacillus spp. e Pseudomonas spp.


Subject(s)
Animals , Bombyx , Anti-Bacterial Agents/pharmacology , Phylogeny , Bacteria/genetics , RNA, Ribosomal, 16S/genetics , Microbial Sensitivity Tests , Larva
2.
Chinese Journal of Natural Medicines (English Ed.) ; (6): 15-30, 2024.
Article in English | WPRIM | ID: wpr-1011008

ABSTRACT

Oleanolic acid (OA), a pentacyclic triterpenoid, exhibits a broad spectrum of biological activities, including antitumor, antiviral, antibacterial, anti-inflammatory, hepatoprotective, hypoglycemic, and hypolipidemic effects. Since its initial isolation and identification, numerous studies have reported on the structural modifications and pharmacological activities of OA and its derivatives. Despite this, there has been a dearth of comprehensive reviews in the past two decades, leading to challenges in subsequent research on OA. Based on the main biological activities of OA, this paper comprehensively summarized the modification strategies and structure-activity relationships (SARs) of OA and its derivatives to provide valuable reference for future investigations into OA.


Subject(s)
Oleanolic Acid , Structure-Activity Relationship , Anti-Inflammatory Agents/pharmacology , Triterpenes , Anti-Bacterial Agents/pharmacology
3.
Journal of Zhejiang University. Science. B ; (12): 65-82, 2024.
Article in English | WPRIM | ID: wpr-1010598

ABSTRACT

Magnesium-doped calcium silicate (CS) bioceramic scaffolds have unique advantages in mandibular defect repair; however, they lack antibacterial properties to cope with the complex oral microbiome. Herein, for the first time, the CS scaffold was functionally modified with a novel copper-containing polydopamine (PDA(Cu2+‍)) rapid deposition method, to construct internally modified (*P), externally modified (@PDA), and dually modified (*P@PDA) scaffolds. The morphology, degradation behavior, and mechanical properties of the obtained scaffolds were evaluated in vitro. The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance. During the prolonged immersion stage, the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release. The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA, while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects. Finally, the PDA(Cu2+)-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model. Overall, it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu2+) modification, and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.


Subject(s)
Animals , Rabbits , Copper/pharmacology , Tissue Scaffolds/chemistry , Bone Regeneration , Anti-Bacterial Agents/pharmacology , Osteogenesis , Calcium , Ions/pharmacology
4.
Arch. argent. pediatr ; 121(5): e202202825, oct. 2023. tab, graf
Article in English, Spanish | LILACS, BINACIS | ID: biblio-1510083

ABSTRACT

Los moduladores de la proteína reguladora transmembrana de fibrosis quística (CFTR) tratan el defecto de esta proteína. El objetivo es describir la evolución de niños con fibrosis quística tratados con lumacaftor/ivacaftor. Se trata de una serie de 13 pacientes de 6 a 18 años con ≥ 6 meses de tratamiento. Se analizaron el volumen espiratorio forzado en el primer segundo (VEF1), puntaje Z del índice de masa corporal (IMC), antibioticoterapia/año, antes del tratamiento y durante 24 meses posteriores. A los 12 meses (9/13) y 24 meses (5/13), la mediana de cambio del porcentaje del predicho VEF1 (ppVEF1) fue de 0,5 pp [-2-12] y 15 pp [8,7-15,2], y del puntaje Z de IMC de 0,32 puntos [-0,2-0,5] y 1,23 puntos [0,3-1,6]. El primer año (11/13) la mediana de días de uso de antibiótico disminuyó de 57 a 28 (oral) y de 27 a 0 (intravenoso). Dos niños evidenciaron eventos adversos asociados.


Cystic fibrosis transmembrane regulator (CFTR) modulators treat defective CFTR protein. Our objective is to describe the course of children with cystic fibrosis treated with lumacaftor/ivacaftor. This is a case series of 13 patients aged 6 to 18 years with ≥ 6 months of treatment. Forced expiratory volume in the first second (FEV1), body mass index (BMI) Z-score, antibiotic therapy/year, before treatment and for 24 months after treatment were analyzed. At 12 months (9/13) and 24 months (5/13), the median change in the percent predicted FEV1 (ppFEV1) was 0.5 pp (-2­12) and 15 pp (8.7­15.2) and the BMI Z-score was 0.32 points (-0.2­0.5) and 1.23 points (0.3­1.6). In the first year, in 11/13 patients, the median number of days of antibiotic use decreased from 57 to 28 (oral) and from 27 to 0 (intravenous). Two children had associated adverse events.


Subject(s)
Humans , Child , Adolescent , Cystic Fibrosis/drug therapy , Forced Expiratory Volume , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Aminophenols/therapeutic use , Hospitals , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Mutation
5.
Journal of Central South University(Medical Sciences) ; (12): 1210-1216, 2023.
Article in English | WPRIM | ID: wpr-1010344

ABSTRACT

OBJECTIVES@#The prevalence of carbapenem-resistant Enterobacterales (CRE) presents a significant challenge in clinical anti-infective treatment. This study aims to investigate drug resistance and the molecular epidemiological characteristics of CRE in our area. Additionally, we seek to evaluate practicality of utilizing carbapenemase inhibitor enhancement test in clinical laboratory.@*METHODS@#Non-repeated CREs isolated from clinical specimens at Xiangya Hospital, Central South University, were collected. Minimum inhibitory concentration (MIC) combined with Kirby-Bauer (KB) assay was used to detect the drug susceptibility of the strains, and 13 carbapenemase-producing genes were detected by PCR. The phenotype of 126 strains of carbapenemase-producing Enterobacterales identified by PCR was detected by the carbapenemase inhibitor enhancement test to understand the agreement between the method and the gold standard PCR results.@*RESULTS@#Among 704 CRE strains examined, we observed significant drug resistance in 501 strains dentified as carbapenemase-producing Enterobacterales (CPE). Klebsiella pneumoniae was the predominant CPE strain, followed by Enterobacter cloacae and Escherichia coli. A total of 9 carbapenemase types were detected, including Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron- encoded metallo-β-lactamases (VIM), imipenemase (IMP), oxacillinase-48 (OXA-48), and rare imipenem-hydrolyzing β-lactamase (IMI), adelaide imipenemase (AIM), Bicêtre carbapenemase (BIC), and guiana extended-spectrum β-lactamase (GES). The detection rate of KPC serine carbapenemase was 61.7% (309/501). The carbapenemase inhibitor enhancement test exhibited a 100% consistency rate for the strains producing Class A serine carbapenemase and/or Class B metallo-β-lactamases.@*CONCLUSIONS@#CRE strains in Changsha, Hunan, China, are wide distribution and exhibit carbapenemase production. The main mechanism of carbapenem resistance in these bacterias is predominatly attributed to the production of KPC serine carbapenemase. The presence of GES and IMI genes carried by Enterobacterales has been detected for the first time in this region. The carbapenemase inhibitor enhancement test has been proven to be an accurate method for detecting CRE producing Class A serine carbapenemase and/or Class B metallo-β-lactamases. This method offers simpicity of operation and ease of results interpretation, making it weel-suited meeting the clinical microbiology laboratory's reguirements for the detection of serine carbapenemase and metallo-β-lactamases.


Subject(s)
Humans , Carbapenems/pharmacology , Molecular Epidemiology , Bacterial Proteins/analysis , beta-Lactamases/analysis , Klebsiella pneumoniae/genetics , Escherichia coli , Microbial Sensitivity Tests , Serine , Anti-Bacterial Agents/pharmacology
6.
Chinese Medical Journal ; (24): 13-23, 2023.
Article in English | WPRIM | ID: wpr-970057

ABSTRACT

Bismuth-containing quadruple therapy (BQT) has long been recommended for Helicobacter pylori ( H. pylori ) eradication in China. Meanwhile, in the latest national consensus in China, dual therapy (DT) comprising an acid suppressor and amoxicillin has also been recommended. In recent years, the eradication rate of H. pylori has reached >90% using DT, which has been used not only as a first-line treatment but also as a rescue treatment. Compared with BQT, DT has great potential for H. pylori eradication; however, it has some limitations. This review summarizes the development of DT and its application in H. pylori eradication. The H. pylori eradication rates of DT were comparable to or even higher than those of BQT or standard triple therapy, especially in the first-line treatment. The incidence of adverse events associated with DT was lower than that with other therapies. Furthermore, there were no significant differences in the effects of dual and quadruple therapies on gastrointestinal microecology. In the short term, H. pylori eradication causes certain fluctuations in the gastrointestinal microbiota; however, in the long term, the gastrointestinal microbiota eventually returns to its normal state. In the penicillin-naïve population, patients receiving DT have a high eradiation rate, better compliance, lower incidence of adverse reactions, and lower primary and secondary resistance to amoxicillin. These findings suggest the safety, efficacy, and potential of DT for H. pylori eradication.


Subject(s)
Humans , Helicobacter Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Helicobacter pylori , Proton Pump Inhibitors , Drug Therapy, Combination , Amoxicillin/therapeutic use , Treatment Outcome
7.
Braz. j. biol ; 83: e249536, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1345531

ABSTRACT

Abstract Seaweeds are a major marine resource that can be explored to develop novel pharmaceutical molecules. The present study showed the presence of unique bioactive components in the petroleum ether extract (PEE) and methanolic extract (ME) of Sargassum tenerrimum. The gas chromatography-mass spectrometry analysis suggested that the PEE of S. tenerrimum contained antibacterial biomolecules: hexadecanoic acid, methyl ester, 17-pentatriacontene, dasycarpidan-1-methanol, and acetate (ester). However, the ME of S. tenerrimum exhibited better antibacterial effect than the PEE due to the presence of the bioactive compounds 1,2-benzenedicarboxylic acid, diisooctyl ester, tetratetracontane, 1-docosene, 1,2-benzenediol, and benzoic acid. Thus, promising antibacterial molecules can be isolated from S. tenerrimum for better therapeutic use.


Resumo As algas marinhas são um importante recurso marinho que pode ser explorado para desenvolver novas moléculas farmacêuticas. O presente estudo mostrou a presença de componentes bioativos únicos no extrato etéreo de petróleo (PEE) e no extrato metanólico (ME) de Sargassum tenerrimum. A análise por cromatografia gasosa-espectrometria de massa sugeriu que o PEE de S. tenerrimum continha biomoléculas antibacterianas: ácido hexadecanoico, éster metílico, 17-pentatriaconteno, dasycarpidan-1-metanol e acetato (éster). Entretanto, o ME de S. tenerrimum exibiu melhor efeito antibacteriano do que o PEE devido à presença dos compostos bioativos ácido 1,2-benzenodicarboxílico, éster diisooctil, tetratetracontano, 1-docosene, 1,2-benzoenodiol e ácido benzoico. Assim, moléculas antibacterianas promissoras podem ser isoladas de S. tenerrimum para melhor uso terapêutico.


Subject(s)
Sargassum , Saudi Arabia , Plant Extracts , Indian Ocean , Anti-Bacterial Agents/pharmacology
8.
Braz. j. biol ; 83: e243332, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1345537

ABSTRACT

Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.


Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.


Subject(s)
Salix , Antifungal Agents/pharmacology , Aspergillus , Rhizopus , Staphylococcus aureus , Plant Extracts/pharmacology , Microbial Sensitivity Tests , Methanol , Escherichia coli , Anti-Bacterial Agents/pharmacology
9.
Chinese Journal of Preventive Medicine ; (12): 416-421, 2023.
Article in Chinese | WPRIM | ID: wpr-969904

ABSTRACT

To explore the clinical distribution and drug resistance characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP), in order to provide reference for the prevention and treatment of CRKP infection. Retrospective analysis was performed on 510 clinical isolates of CRKP from January 2017 to December 2021, and strain identification and drug sensitivity tests were conducted by MALDI-TOF mass spectrometer and VITEK-2 Compact microbial drug sensitivity analyzer. The carbapenemase phenotype of CRKP strain was detected by carbapenemase inhibitor enhancement test. The CRKP strain was further categorized by immunochromogenic method and polymerase chain reaction (PCR) was used for gene detection. The results showed that 302 strains (59.2%) were derived from sputum, 127 strains (24.9%) from urine and 47 strains (9.2%) from blood. 231 (45.3%) were mainly distributed in intensive care, followed by 108 (21.2%) in respiratory medicine and 79 (15.5%) in neurosurgery. Drug susceptibility test result shows that the resistant rate of tigecycline increased from 1.0% in 2017 to 10.1% in 2021, the difference was statistically significant (χ2=14.444,P<0.05). The results of carbapenemase inhibitor enhancement test showed that 461 carbapenemase strains (90.4%) of 510 CRKP strains, including 450 serinase strains (88.2%), 9 metalloenzyme strains (1.8%), and 2 strains (0.4%) produced both serine and metalloenzyme. 49 strains (9.6%) did not produce enzymes. Further typing by immunochromogenic assay showed that 461 CRKP strains were KPC 450 (97.6%) and IMP 2 (0.4%). 7 NDM (1.5%); 2 strains of KPC+NDM (0.4%); PCR results were as follows: 450 strains of blaKPC (97.6%), 2 strains of blaIMP (0.4%), 7 strains of blaNDM (1.5%), and 2 strains of blaKPC+NDM (0.4%). In conclusion, CRKP strains mainly originated from sputum specimens and distributed in intensive care department, and the drug resistance characteristics were mainly KPC type in carbapenemase production. Clinical microbiology laboratory should strengthen the monitoring of CRKP strains, so as to provide reference for preventing CRKP infection and reducing the production of bacterial drug resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Klebsiella pneumoniae/genetics , Hospital Distribution Systems , Retrospective Studies , Microbial Sensitivity Tests , beta-Lactamases/genetics , Bacterial Proteins/genetics , Drug Resistance, Bacterial/genetics
10.
Chinese Journal of Preventive Medicine ; (12): 241-246, 2023.
Article in Chinese | WPRIM | ID: wpr-969873

ABSTRACT

To understand the clinical characteristics of Staphylococcus aureus bloodstream infection and the main risk factors affecting clinical prognosis, providing a reference for clinical prevention and control of Staphylococcus aureus bloodstream infection. In this study, the clinical data of 152 patients with Staphylococcus aureus bloodstream infection admitted to Guangdong Provincial People's Hospital from January 2019 to December 2021 were retrospectively analyzed by reviewing the electronic medical record system, including underlying diseases, clinical characteristics, risk factors, and bacterial resistance. Statistical methods such as Chi-Squared Test and t Test were used to analyze the related risk factors that may affect the clinical characteristics and prognosis of patients with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection, then the variables with P<0.05 in univariate analysis were included in the multivariate logistic regression model to analyze the independent risk factors of poor prognosis. The results showed among 152 patients with Staphylococcus aureus bloodstream infection, 50 patients (32.89%) were infected with MRSA. In comparison, 102 patients (67.11%) were infected with methicillin-sensitive Staphylococcus aureus (MSSA). Except for rifampicin, the resistance rate of MRSA to commonly used antibiotics was all higher than that of MSSA, and the difference was statistically significant (Chi-square values were 8.272, 11.972, 4.998, 4.776, respectively;all P-values are less than 0.05). Strains resistant to vancomycin, linezolid, and quinupristin/dalfopristin were not found. In the MRSA group, indwelling catheter and drainage tube, carbapenems, and β-lactamase inhibitor treatment were significantly higher than the MSSA group. The difference was statistically significant (P<0.05). The incidence of poor prognosis of bloodstream infection in the MRSA group was higher than that in the MSSA group (34.00% vs 13.73%), and the difference was statistically significant (χ2=8.495, P<0.05). No independent risk factors associated with poor prognosis were found in the included patients with MRSA bloodstream infection.Multivariate Logistic regression model analysis showed that solid malignant tumors (OR=13.576, 95%CI: 3.352-54.977, P<0.05), mechanical ventilation (OR=7.468, 95%CI: 1.398-39.884, P<0.05) were the most important independent risk factors for poor prognosis in patients with Staphylococcus aureus bloodstream infection. In summary, the poor prognosis rate of MRSA bloodstream infection is higher than that of MSSA. The clinical evaluation of related risk factors should be strengthened, targeted prevention and control interventions should be taken to improve the prognosis of patients with Staphylococcus aureus bloodstream infection, and the use of antibiotics should be rational and standardized, to control bacterial infection and drug resistance effectively .


Subject(s)
Humans , Methicillin-Resistant Staphylococcus aureus , Staphylococcus aureus , Retrospective Studies , Prognosis , Staphylococcal Infections/microbiology , Anti-Bacterial Agents/pharmacology , Methicillin/therapeutic use , Sepsis
11.
Chinese Journal of Biotechnology ; (12): 1314-1331, 2023.
Article in Chinese | WPRIM | ID: wpr-981140

ABSTRACT

Stenotrophomonas species are non-fermentative Gram-negative bacteria that are widely distributed in environment and are highly resistant to numerous antibiotics. Thus, Stenotrophomonas serves as a reservoir of genes encoding antimicrobial resistance (AMR). The detection rate of Stenotrophomonas is rapidly increasing alongside their strengthening intrinsic ability to tolerate a variety of clinical antibiotics. This review illustrated the current genomics advances of antibiotic resistant Stenotrophomonas, highlighting the importance of precise identification and sequence editing. In addition, AMR diversity and transferability have been assessed by the developed bioinformatics tools. However, the working models of AMR in Stenotrophomonas are cryptic and urgently required to be determined. Comparative genomics is envisioned to facilitate the prevention and control of AMR, as well as to gain insights into bacterial adaptability and drug development.


Subject(s)
Stenotrophomonas/genetics , Drug Resistance, Bacterial/genetics , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria , Genomics , Microbial Sensitivity Tests
12.
Biomedical and Environmental Sciences ; (12): 406-417, 2023.
Article in English | WPRIM | ID: wpr-981069

ABSTRACT

OBJECTIVE@#To explore the genotyping characteristics of human fecal Escherichia coli( E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.@*METHODS@#Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS).@*RESULTS@#This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24).@*CONCLUSION@#We developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.


Subject(s)
Humans , Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Multilocus Sequence Typing , Genotype , Beijing , Drug Resistance, Multiple, Bacterial/genetics , Anti-Bacterial Agents/pharmacology , Diarrhea , Microbial Sensitivity Tests
13.
Acta Academiae Medicinae Sinicae ; (6): 783-788, 2023.
Article in Chinese | WPRIM | ID: wpr-1008132

ABSTRACT

Objective To explore the inhibitory effects and mechanisms of benzodiazepines on Helicobacter pylori (Hp).Methods The Hp international standard strain ATCC43504 was treated with benzodiazepines diazepam,midazolam,and remimazolam,respectively.The treatments with amoxicillin and clarithromycin were taken as the positive controls,and that with water for injection as the negative control.The inhibition zone of each drug was measured by the disk diffusion method.The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of each drug against Hp were determined.Hp suspension was configured and treated with diazepam and midazolam,respectively.The bacterial suspension without drug added was used as the control group.The concentration of K+ in each bacterial suspension was measured by an automatic biochemical analyzer before drug intervention(T0)and 1(T1),2(T2),3(T3),4(T4),5(T5),6(T6),and 7 h(T7)after intervention.Hp urease was extracted and treated with 1/2 MIC diazepam,1 MIC diazepam,2 MIC diazepam,1/2 MIC midazolam,1 MIC midazolam,2 MIC midazolam,1 mg/ml acetohydroxamic acid,and water for injection,respectively.The time required for the rise from pH 6.8 to pH 7.7 in each group was determined by the phenol red coloring method.Results The inhibition zones of diazepam,midazolam,remimazolam,amoxicillin,clarithromycin,and water for injection against Hp were 52.3,42.7,6.0,72.3,60.8,and 6.0 mm,respectively.Diazepam and midazolam showed the MIC of 12.5 μg/ml and 25.0 μg/ml and the MBC of 25 μg/ml and 50 μg/ml,respectively,to Hp.The concentrations of K+ in the diazepam,midazolam,and control groups increased during T1-T7 compared with those at T0(all P<0.01).The concentration of K+ in diazepam and midazolam groups during T1-T4 was higher than that in the control group(all P<0.01).The time of inhibiting urease activity in the 1/2 MIC diazepam,1 MIC diazepam,2 MIC diazepam,1/2 MIC midazolam,1 MIC midazolam,and 2 MIC midazolam groups was(39.86±5.11),(36.52±6.65),(38.58±4.83),(39.25±6.19),(36.36±4.61),and(35.81±6.18)min,respectively,which were shorter than that in the acetohydroxamic acid group(all P<0.01)and had no significance differences from that in the water for injection group(all P>0.05).Conclusion Diazepam and midazolam exerted inhibitory effects on Hp,which may be related to the cleavage of Hp cells rather than inhibiting urease.


Subject(s)
Midazolam , Helicobacter pylori , Urease , Clarithromycin/pharmacology , Benzodiazepines/pharmacology , Diazepam/pharmacology , Amoxicillin , Water , Anti-Bacterial Agents/pharmacology
14.
Chinese Journal of Biotechnology ; (12): 4189-4203, 2023.
Article in Chinese | WPRIM | ID: wpr-1008020

ABSTRACT

Silver nanoparticles (AgNPs) is known as one of the most valuable metal nanoparticles in antibacterial and anticancer application. AgNPs-resistant bacteria has been documented, but it is unclear whether cancer cells can also escape the anti-cancer effect of AgNPs. In this study, we aimed to investigate this phenomenon and its underlying mechanism. The antibacterial activity and cytotoxicity of AgNPs were measured in the presence of HeLa cell metabolites. The status of AgNPs in the system associated with metabolites were characterized by UV-Vis, Zetasizer Nano ZS, and transmission electron microscopy. Non-targeted metabolomics was used to reveal the metabolites components that bind with AgNPs. HeLa cells were injected intraperitoneally to establish the tumor-bearing mice model, and the stability of AgNPs in mice serum was analyzed. The results manifested that HeLa cell metabolites inhibited the anticancer and antibacterial effects of AgNPs in a dose-dependent manner by causing AgNPs aggregation. Effective metabolites that inhibited the biological activity of AgNPs were stable in 100 ℃, insoluble in chloroform, containing sulfur elements, and had a molecular weight less than 1 kDa in molecular weight. There were 115 compounds bound with AgNPs. In vitro experiments showed that AgNPs aggregation occurred only when the concentration of α-ketoglutarate (AKG) and glutathione (GSH) together reached a certain threshold. Interestingly, the concentration of AKG and GSH in HeLa cellular metabolites was 10 and 6 times higher than that in normal cervical epithelial cells, respectively, which explained why the threshold was reached. Furthermore, the stability of AgNPs in the serum of tumor-bearing mice decreased by 20% (P < 0.05) compared with the healthy mice. In conclusion, our study demonstrates that HeLa cells escaped the anti-cancer effect of AgNPs through the synergistic effect of AKG and GSH, suggesting the need to develop strategies to overcome this limitation.


Subject(s)
Humans , Animals , Mice , HeLa Cells , Silver/pharmacology , Ketoglutaric Acids/pharmacology , Metal Nanoparticles , Anti-Bacterial Agents/pharmacology , Glutathione , Microbial Sensitivity Tests
15.
Chinese Journal of Pediatrics ; (12): 690-694, 2023.
Article in Chinese | WPRIM | ID: wpr-1013156

ABSTRACT

Objective: To understand the characteristics of bacterial meningitis after pediatric neurosurgical procedures. Methods: This was a retrospective observational study. From January 2016 to December 2022, 64 children diagnosed with post-neurosurgical bacterial meningitis based on positive cerebrospinal fluid (CSF) culture in Department of Neurosurgery of Shanghai Children's Medical Center were selected as the study population. The clinical characteristics, onset time, routine biochemical indexes of cerebrospinal fluid before anti infection treatment, bacteriology characteristics and sensitivity to antibiotics of bacteria cultured from cerebrospinal fluid were analyzed. Based on the CSF culture results, the patients were divided into the Gram-positive bacteria infection group and the Gram-negative bacteria infection group. The clinical characteristics of the two groups were compared using t-tests or Wilcoxon rank-sum tests, and chi-square tests. Results: There were 64 children,42 boys and 22 girls, with onset age of 0.83 (0.50, 1.75) years. Seventy cases of post-neurosurgical bacterial meningitis occurred in the 64 children, of which 15 cases (21%) in spring, 23 cases (33%) in summer, 19 cases (27%) in autumn, and 13 cases (19%) in winter. The time of onset was 3.5 (1.0, 10.0) months after surgery; 15 cases (21%) occurred within the first month after the surgery, and 55 cases (79%) occurred after the first month. There were 38 cases (59%) showing obvious abnormal clinical manifestations, fever 36 cases (56%), vomiting 11 cases (17%). Forty-eight cases (69%) were caused by Gram-positive bacteria, with Staphylococcus epidermidis 24 cases; 22 cases (31%) were caused by Gram-negative bacteria, with Acinetobacter baumannii the prominent pathogen 7 cases. The Gram-positive bacterial infection was more common in summer than the Gram-negative bacterial infection (20 cases (42%) vs. 3 cases (14%), χ2=5.37, P=0.020), while the Gram-negative bacterial infection was more in autumn and within the first month after surgery than the Gram-positive bacterial infection (11 cases (50%) vs. 8 cases (17%), 15 cases (67%) vs. 5 cases (33%), χ2=8.48, 9.02; P=0.004, 0.003). Gram-positive bacteria resistant to vancomycin and Acinetobacter baumannii resistant to polymyxin were not found. However, Acinetobacter baumannii showed only 45% (10/22) susceptibility to carbapenem antibiotics. Conclusions: The clinical presentation of post-neurosurgical bacterial meningitis in children is atypical. Gram-positive bacteria are the main pathogens causing post-neurosurgical bacterial meningitis; Gram-negative bacterial meningitis are more likely to occur in autumn and within the first month after surgery. Acinetobacter baumannii has a high resistance rate to carbapenem antibiotics, which should be taken seriously.


Subject(s)
Male , Female , Humans , Child , China/epidemiology , Anti-Bacterial Agents/pharmacology , Meningitis, Bacterial/diagnosis , Gram-Negative Bacterial Infections/drug therapy , Gram-Positive Bacteria , Gram-Positive Bacterial Infections/drug therapy , Carbapenems , Retrospective Studies , Microbial Sensitivity Tests , Drug Resistance, Bacterial
16.
Journal of Integrative Medicine ; (12): 487-495, 2023.
Article in English | WPRIM | ID: wpr-1010955

ABSTRACT

OBJECTIVE@#This study tests the efficacy of Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMC), baicalin (BA) and silver titanate (ST) in a wound dressings to fight infection, promote healing and provide superior biocompatibility.@*METHODS@#The antibacterial activity of BA and ST was evaluated in vitro using the inhibition zone method. BA/ST/BSP/CMC porous sponge dressings were prepared and characterized. The biocompatibility of BA/ST/BSP/CMC was assessed using the cell counting kit-8 assay. The therapeutic effect of BA/ST/BSP/CMC was further investigated using the dorsal skin burn model in Sprague-Dawley rats.@*RESULTS@#The wound dressing had good antibacterial activity against Escherichia coli and Staphylococcus aureus through BA and ST, while the combination of BSP and CMC played an important role in promoting wound healing. The BA/ST/BSP/CMC porous sponge dressings were prepared using a freeze-drying method with the concentrations of BA and ST at 20 and 0.83 mg/mL, respectively, and the optimal ratio of 5% BSP to 4% CMC was 1:3. The average porosity, water absorption and air permeability of BA/ST/BSP/CMC porous sponge dressings were measured to be 90.43%, 746.1% and 66.60%, respectively. After treatment for 3 and 7 days, the healing rates of the BA/ST/BSP/CMC group and BA/BSP/CMC group were significantly higher than those of the normal saline (NS) group and silver sulfadiazine (SSD) group (P < 0.05). Interleukin-1β expression in the BA/ST/BSP/CMC group at 1 and 3 days was significantly lower than that in the other three groups (P < 0.05). After being treated for 3 days, vascular endothelial growth factor expression in the BA/BSP/CMC group and BA/ST/BSP/CMC group was significantly higher than that in the NS group and SSD group (P < 0.05). Inspection of histological sections showed that the BA/ST/BSP/CMC group and BA/BSP/CMC group began to develop scabbing and peeling of damaged skin after 3 days of treatment, indicating accelerated healing relative to the NS group and SSD group.@*CONCLUSION@#The optimized concentration of BA/ST/BSP/CMC dressing was as follows: 6 mg BSP, 14.4 mg CMC, 0.5 mg ST and 12 mg BA. The BA/ST/BSP/CMC dressing, containing antibacterial constituents, was non-cytotoxic and effective in accelerating the healing of burn wounds, making it a promising candidate for wound healing. Please cite this article as: Gong YR, Zhang C, Xiang X, Wang ZB, Wang YQ, Su YH, Zhang HQ. Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing. J Integr Med. 2023; 21(5): 487-495.


Subject(s)
Rats , Animals , Chitosan/pharmacology , Silver/pharmacology , Porosity , Vascular Endothelial Growth Factor A/pharmacology , Rats, Sprague-Dawley , Wound Healing , Polysaccharides/pharmacology , Bandages , Burns/drug therapy , Anti-Bacterial Agents/pharmacology , Silver Sulfadiazine/pharmacology
17.
Chinese Journal of Preventive Medicine ; (12): 557-565, 2023.
Article in Chinese | WPRIM | ID: wpr-985444

ABSTRACT

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.


Subject(s)
Humans , Colistin/pharmacology , Anti-Bacterial Agents/pharmacology , Escherichia coli Infections/epidemiology , Escherichia coli Proteins/genetics , Drug Resistance, Bacterial/genetics , China/epidemiology , Escherichia coli , Plasmids/genetics , Microbial Sensitivity Tests
18.
Chinese Journal of Preventive Medicine ; (12): 508-515, 2023.
Article in Chinese | WPRIM | ID: wpr-984765

ABSTRACT

Objective: To analyze the drug resistance and genomic characteristics of Salmonella enterica serovar London isolated from clinical and food sources in Hangzhou City from 2017 to 2021. Methods: A total of 91 Salmonella enterica serovar London strains isolated from Hangzhou City from 2017 to 2021 were analyzed for drug susceptibility, pulsed field gel electrophoresis (PFGE) typing and whole genome sequencing. Multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST) and detection of drug resistance genes were performed by using the sequencing data. Phylogenetic analysis was conducted to compare the 91 genomes from Hangzhou City with 347 genomes from public databases. Results: No significant difference in the drug resistance rate was observed between clinical strains and food strains to 18 drugs in Hangzhou City(all P>0.05), and the multidrug resistance (MDR) rate was 75.8% (69/91). Most strains were resistant to 7 drug classes simultaneously. One strain was resistant to Polymyxin E as well as positive for mcr-1.1, and 50.5% (46/91) of the strains were resistant to Azithromycin and were positive for mph(A). All 91 Salmonella enterica serovar London strains were ST155, which were subdivided into 44 molecular types by PFGE and 82 types by cgMLST. Phylogenetic analysis showed that most strains from Hangzhou City (83/91) were clustered together, and a small number of human isolates from Europe, North America and pork isolates from Hubei and Shenzhen were mixed in the cluster. Other strains from Hangzhou City (8/91) were closely related to strains from Europe, America and Southeast Asia. Strains isolated from pork were the most closely related to clinical strains. Conclusion: The epidemic of Salmonella enterica serovar London in Hangzhou City is mainly caused by the spread of ST155 strains, which is mainly transmitted locally. At the same time, cross-region transmission to Europe, North America, Southeast Asia, and other provinces and cities in China may also occur. There is no significant difference in the drug resistance rate between clinical strains and food strains, and a high level of MDR is found in the strains. Clinical infection of Salmonella enterica serovar London may be closely related to pork consumption in Hangzhou City.


Subject(s)
Humans , Salmonella enterica/genetics , Serogroup , Anti-Bacterial Agents/pharmacology , Multilocus Sequence Typing , Cities , London , Clonidine , Phylogeny , Genomics , Drug Resistance , Electrophoresis, Gel, Pulsed-Field , Microbial Sensitivity Tests
19.
Chinese Journal of Hematology ; (12): 479-483, 2023.
Article in Chinese | WPRIM | ID: wpr-984647

ABSTRACT

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.


Subject(s)
Humans , Bacteremia/epidemiology , Cefoperazone , Sulbactam , Retrospective Studies , Drug Resistance, Bacterial , Microbial Sensitivity Tests , Hematologic Neoplasms , Sepsis , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria , Gram-Positive Bacteria , Piperacillin, Tazobactam Drug Combination , Escherichia coli
20.
Chinese Journal of Cellular and Molecular Immunology ; (12): 857-862, 2023.
Article in Chinese | WPRIM | ID: wpr-1009441

ABSTRACT

Platelets not only have hemostatic function, but can also directly or indirectly recognize pathogenic microorganisms and the signals they produce to capture and destroy them through membrane receptors. They can collaborate with various components of the body's immune system by releasing of intraplatelet particulate matter, cytokines and chemokines to perform bactericidal functions. And it can also play a bactericidal role by swallowing pathogens, releasing antimicrobial proteins and chemokines and activating and enhancing other specialized anti-inflammatory cells bactericidal effect, such as leukocytes and so on. However, the bacteriostatic composition and bacteriostatic mechanism of platelets remain unclear, so attention should be paid to the immune mechanism and bacteriostatic effect of platelets.


Subject(s)
Blood Platelets , Anti-Bacterial Agents/pharmacology , Cytokines , Leukocytes , Particulate Matter
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