2.Analysis of Pathogenic Bacterial Spectrum, Drug Resistance and Risk Factors for Mortality of Bloodstream Infection in Patients with Hematologic Diseases.
Qian GUO ; Xin-Wei WANG ; Xin-Yue CHEN ; Jie ZHAO ; Shao-Long HE ; Wei-Wei TIAN ; Liang-Ming MA
Journal of Experimental Hematology 2023;31(5):1556-1562
OBJECTIVE:
To analyze the pathogenic bacterial spectrum, drug resistance, and risk factors associated with multidrug-resistant bacterial infection and mortality in patients with hematologic diseases complicated by bloodstream infections, so as to provide reference for rational drug use and improving prognosis.
METHODS:
Positive blood culture specimens of patients with hematologic diseases in two Class A tertiary hospitals of Shanxi province from January 2019 to December 2021 were retrospectively analyzed. Pathogen distribution, drug resistance and outcomes of patients with bloodstream infection were investigated, then the multivariate logistic analysis was performed to analyze the risk factors of multidrug-resistant bacterial infection and factors affecting prognosis.
RESULTS:
203 strains of pathogens were identified, mainly Gram-negative bacteria (GNB) (69.46%, 141/203), of which Escherichia coli (E.coli) had the highest incidence (41.13%, 58/141), followed by Klebsiella pneumoniae (20.57%, 29/141) and Pseudomonas aeruginosa (12.77%, 18/141). Extended-spectrum beta-lactamase (ESBL)-producing E.coli and Klebsiella pneumoniae were 46.55% (27/58) and 37.93% (11/29), respectively. Carbapenem-resistant Gram-negative bacteria accounted for 10.64% (15/141). And Gram-positive bacteria accounted for 27.59% (56/203), Staphylococcus epidermidis, Streptococcus pneumoniae, and Staphylococcus aureus were the most frequently isolated pathogen among Gram-positive bacteria (14.29%, 12.50% and 10.71%, respectively), of which methicillin-resistant Staphylococcus aureus accounted for 33.33% (2/6), coagulase-negative staphylococci accounted for 87.50% (7/8), without vancomycin- or linezolid-resistant strain. Additionally, fungi accounted for 2.95% (6/203), all of which were Candida. Multidrug-resistant Gram-negative bacteria (MDR-GNB) accounted for 53.90% (76/141). Duration of neutropenia >14 days was a risk factor for developing MDR-GNB infection. The 30-day all-cause mortality was 10.84%. Multivariate logistic regression analysis showed that the significant independent risk factors for mortality were age≥60 years (P <0.01, OR =5.85, 95% CI: 1.80-19.07) and use of vasopressor drugs (P <0.01, OR =5.89, 95% CI: 1.83-18.94).
CONCLUSION
The pathogenic bacteria of bloodstream infection in patients with hematological diseases are widely distributed, and the detection rate of multidrug-resistant bacteria is high. The clinicians should choose suitable antibiotics according to the results of bacterial culture and antibiotic susceptibility test.
Humans
;
Middle Aged
;
Bacteremia/mortality*
;
Bacteria/isolation & purification*
;
Drug Resistance
;
Drug Resistance, Bacterial
;
Gram-Negative Bacteria
;
Hematologic Diseases/complications*
;
Methicillin-Resistant Staphylococcus aureus
;
Retrospective Studies
;
Risk Factors
;
Sepsis/mortality*
3.Solid Tumors With Cold Agglutinins:Report of Two Cases and Literature Review.
Hong-Xiang XIE ; Ru-Hui PAN ; Fei-Fei ZHOU ; Su-Mei WANG ; Su-Feng CHEN ; Wen-Jing CAO ; Jia-Jun JI
Acta Academiae Medicinae Sinicae 2023;45(4):689-694
Cold agglutinins(CA),autoantibodies against the antigen I or i on the surface of red blood cells,are mainly of IgM class,and the majority have κ light chains.They can lead to red blood cell agglutination at decreased body temperature and are usually associated with infections,drug reactions,autoimmune diseases,and hematological malignancies.However,solid tumors with CA are rare.We reported two cases of CA in the peripheral blood of patients with solid tumors.Peripheral complete blood cell count of the patients at admission showed reduced erythrocyte count and hematocrit,mismatching between erythrocyte count and hemoglobin,abnormally elevated levels of mean corpuscular hemoglobin and mean cell hemoglobin concentration.Peripheral blood smear showed erythrocyte aggregation.After the sample was preheated at 37 ℃ for 30 min,the reversibility of red blood cell aggregation was observed,and the erythrocyte parameters were corrected.
Humans
;
Autoantibodies/isolation & purification*
;
Female
;
Breast Neoplasms/immunology*
;
Ovarian Neoplasms/immunology*
4.Single-copy Loss of Rho Guanine Nucleotide Exchange Factor 10 ( arhgef10) Causes Locomotor Abnormalities in Zebrafish Larvae.
Yi ZHANG ; Ming Xing AN ; Chen GONG ; Yang Yang LI ; Yu Tong WANG ; Meng LIN ; Rong LI ; Chan TIAN
Biomedical and Environmental Sciences 2022;35(1):35-44
OBJECTIVE:
To determine if ARHGEF10 has a haploinsufficient effect and provide evidence to evaluate the severity, if any, during prenatal consultation.
METHODS:
Zebrafish was used as a model for generating mutant. The pattern of arhgef10 expression in the early stages of zebrafish development was observed using whole-mount in situ hybridization (WISH). CRISPR/Cas9 was applied to generate a zebrafish model with a single-copy or homozygous arhgef10 deletion. Activity and light/dark tests were performed in arhgef10 -/-, arhgef10 +/-, and wild-type zebrafish larvae. ARHGEF10 was knocked down using small interferon RNA (siRNA) in the SH-SY5Y cell line, and cell proliferation and apoptosis were determined using the CCK-8 assay and Annexin V/PI staining, respectively.
RESULTS:
WISH showed that during zebrafish embryonic development arhgef10 was expressed in the midbrain and hindbrain at 36-72 h post-fertilization (hpf) and in the hemopoietic system at 36-48 hpf. The zebrafish larvae with single-copy and homozygous arhgef10 deletions had lower exercise capacity and poorer responses to environmental changes compared to wild-type zebrafish larvae. Moreover, arhgef10 -/- zebrafish had more severe symptoms than arhgef10 +/- zebrafish. Knockdown of ARHGEF10 in human neuroblastoma cells led to decreased cell proliferation and increased cell apoptosis.
CONCLUSION
Based on our findings, ARHGEF10 appeared to have a haploinsufficiency effect.
Animals
;
Annexin A5
;
Apoptosis
;
Blotting, Western
;
CRISPR-Associated Protein 9
;
CRISPR-Cas Systems
;
Cell Line
;
Cell Proliferation
;
Cells, Cultured
;
Flow Cytometry
;
Genotype
;
Humans
;
In Situ Hybridization
;
Larva/physiology*
;
Phenotype
;
RNA/isolation & purification*
;
Real-Time Polymerase Chain Reaction/standards*
;
Rho Guanine Nucleotide Exchange Factors/metabolism*
;
Sincalide/analysis*
;
Spectrophotometry/methods*
;
Zebrafish/physiology*
5.Development of a Recombinase-aided Amplification Combined With Lateral Flow Dipstick Assay for the Rapid Detection of the African Swine Fever Virus.
Jiang Shuai LI ; Yan Zhe HAO ; Mei Ling HOU ; Xuan ZHANG ; Xiao Guang ZHANG ; Yu Xi CAO ; Jin Ming LI ; Jing MA ; Zhi Xiang ZHOU
Biomedical and Environmental Sciences 2022;35(2):133-140
OBJECTIVE:
To establish a sensitive, simple and rapid detection method for African swine fever virus (ASFV) B646L gene.
METHODS:
A recombinase-aided amplification-lateral flow dipstick (RAA-LFD) assay was developed in this study. Recombinase-aided amplification (RAA) is used to amplify template DNA, and lateral flow dipstick (LFD) is used to interpret the results after the amplification is completed. The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid. In addition, 30 clinical samples were tested to evaluate the performance of the RAA assay.
RESULTS:
The RAA-LFD assay was completed within 15 min at 37 °C, including 10 min for nucleic acid amplification and 5 minutes for LFD reading results. The detection limit of this assay was found to be 200 copies per reaction. And there was no cross-reactivity with other swine viruses.
CONCLUSION
A highly sensitive, specific, and simple RAA-LFD method was developed for the rapid detection of the ASFV.
African Swine Fever/virology*
;
African Swine Fever Virus/isolation & purification*
;
Animals
;
Nucleic Acid Amplification Techniques/methods*
;
Recombinases/chemistry*
;
Sensitivity and Specificity
;
Swine
;
Viral Proteins/genetics*
6.Case Report of Acute Peritonitis with Blood Infection of Neisseria meningitidis.
Xian XIA ; Jing LYU ; Xuan CAI ; Yuan Liang HU ; Fei HE ; Guo Ming LI ; Hong Mei YANG
Biomedical and Environmental Sciences 2022;35(2):151-154
Acute Disease
;
Aged
;
Anti-Bacterial Agents/therapeutic use*
;
Bacteremia/microbiology*
;
Female
;
Hepatitis B, Chronic/complications*
;
Hepatitis C, Chronic/complications*
;
Humans
;
Hypersplenism/complications*
;
Liver Cirrhosis/complications*
;
Meningococcal Infections/microbiology*
;
Neisseria meningitidis/isolation & purification*
;
Peritonitis/microbiology*
7.Impact of Bacillus thuringiensis on inhibiting certain Alternaria alternata’s mycotoxins isolated from infected potatoes
Nesrine Hassan Youssef ; Mayada Ali Sabra
Malaysian Journal of Microbiology 2022;18(2):163-169
Aims:
Potatoes are considered one of the most strategic vegetable crops all over the world. Alternaria alternata has recently contaminated certain potatoes farms in different regions in Egypt. Among thirteen samples from fifteen regions were studied in a precedent study. Our study was aimed to investigate the effect of Bacillus thuringiensis subsp. Kurosaki suspension on inhibiting the growth of the three tested isolates of A. alternata and minimizing their mycotoxins production in vitro using three isolates with three levels of highly, moderate and low pathogenicity with unequal amounts of dual mycotoxins production.
Methodology and results:
Three isolates of A. alternata from three regions, Kom Hamada (KH3), Alamin (Alam1) and Nobaria (NO3), which were determined as a producer of tenuazonic acid (TeA) and alternariol monomethyl ether (AME) toxins. Bacillus thuringiensis (Bt) use as commercial fungicide was applied with three suspension concentrations (75, 150 and 300 μg/mL) as inhibitor for the two mycotoxins. Our results illustrated that the three tested isolates recorded high TeA and AME inhibition efficacies by increasing the Bt suspension concentration. The highest inhibitory concentration of Bt was at concentration 75 μg/mL for isolated from Nobaria third region (NO3) and Alam1 it was (99.83 and 99.74%) for mycotoxin (AME) while, TeA mycotoxin had the most inhibition percentage (99.58%) at concentration 150 μg/mL for the isolate (NO3).
Conclusion, significance and impact of study
The preliminary results of the study suggest that B. thuringiensis spores’ suspension with different concentrations can be used as anti-mycotoxigenic agents to inhibit the (TeA) and (AME) mycotoxins produced by Alternaria alternata.
Bacillus thuringiensis
;
Alternaria--isolation &
;
purification
;
Solanum tuberosum
8.In vitro evaluation of α-glucosidase inhibitor and antioxidant activity of Lactobacillus isolates and their antidiabetic potential
Ni Nyoman Puspawati ; Nyoman Semadi Antara ; I Dewa Gde Mayun Permana ; I Dewa Made Sukrama
Malaysian Journal of Microbiology 2022;18(2):192-203
Aims:
This study aimed to evaluate antidiabetic potential of indigenous Lactobacillus isolates by measuring the ability of α-glucosidase inhibitory (AGI) and antioxidant activity. The mechanism of probiotics as antidiabetic can occur through the AGI and antioxidant activity of LAB, which is able to suppress oxidative stress that causes chronic inflammation and pancreatic β cell apoptosis, and then through the ability to produce exopolysaccharide (EPS) and short chain fatty acids (SCFA).
Methodology and results:
MRS broth enriched with 10% glucose was selected as the growth medium for Lactobacillus. The growth medium was then centrifuged to obtain CFS and CFE was produced by extracting the medium with 96% ethanol as a solvent. The results showed that Lactobacillus pentosus MK42 had the highest AGI activity of 80.32 ± 2.20%. Antioxidant activity was not significantly different (P>0.05) among the tested Lactobacillus isolates. Lactobacillus paracasei RK41 produced the highest EPS (360.13 ± 50.01 mg/L), which was not significantly different (P>0.05) from Lactobacillus plantarum1 RB210. All Lactobacillus isolates were able to produce acetic acid, but not all were able to produce propionic and butyric acid. The highest propionic acid was produced by L. plantarum1 RB210 at 0.40 ± 0.31 mmol/L and the highest butyric acid was produced by L. plantarum1 MK2 at 0.22 ± 0.08 mmol/L.
Conclusion, significance and impact of study
The results show definitively that indigenous Lactobacillus isolates have considerable α-glucosidase inhibitor, antioxidant activity and the ability to produce of EPS and SCFA. This preliminary study suggests the use of indigenous Lactobacillus isolates which have the potential as antidiabetic agent, although the responsible compounds are unknown.
alpha-Glucosidases
;
Antioxidants
;
Lactobacillus--isolation &
;
purification
;
Hypoglycemic Agents
9.Probiotic potential of lactic acid bacteria isolated from Vietnamese sour-fermented fish product
Nguyen Pham Anh Thi ; Tran Huu Hau ; Nguyen Thi Nhu Huynh ; Huynh Van Liem ; Tran Kieu Dieu Thi ; Do Phuong Kieu ; Dang Huy Hoa ; Nguyen Thanh Nha ; Nguyen Pham Thien Trang ; Le Nguyen Khoi Nguyen ; Truong Thi Bich Van ; Do Tan Khang
Malaysian Journal of Microbiology 2022;18(2):222-226
Aims:
To isolate and characterize the lactic acid bacteria (LAB) strains from the “mam chua ca ro” (sour fermented fish) in the South of Vietnam and investigate their potential anti-bacterial properties.
Methodology and results:
Four LAB strains (MCR1, MCR2, MCR3 and MCR4) were isolated from the "mam chua ca ro" product and their anti-bacterial activity was determined using the spot assay and the paper disc diffusion method. The isolated LABs can inhibit Escherichia coli ATCC 25922, Staphyloccocus aureus ATCC 25923 and Vibrio parahaemolyticus BV016 and produce bacteriocin to control the growth of E. coli ATCC 25922 and S. aureus ATCC 25923, except V. parahaemolyticus. MCR2 was chosen to sequence 16S rRNA of Pediococcus acidilactic.
Conclusion, significance and impact of study
On the basis of their prominent anti-pathogenic bacteria activity, LAB strains isolated from Vietnamese sour-fermented fish products were verified as prospective probiotics.
Lactobacillales--isolation &
;
purification
;
Pediococcus acidilactici
10.Isolation of bacteria with plant growth-promoting activities from a foliar biofertilizer
Xin Yen Tor ; Wai Keat Toh ; Pek Chin Loh ; Hann Ling Wong
Malaysian Journal of Microbiology 2022;18(3):315-321
Aims:
Plant growth-promoting bacteria are the key components of a biofertilizer. This study was aimed to isolate and identify the predominant bacteria found in a foliar biofertilizer and characterizes the potential of the bacterial isolates as plant growth promoters.
Methodology and results:
Potential bacteria with plant growth-promoting activities were isolated from a foliar biofertilizer on HiCrome™ Bacillus agar and Nutrient agar. Bacteria with unique colonial morphology were selected and categorized by Gram’s differential staining. Subsequently, the bacterial isolates were being further characterized for plant growth-promoting potentials, such as the production of indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and siderophore; as well as the ability of nitrogen fixation and phosphate/potassium solubilization. Based on the characterized traits, three bacterial isolates, namely M17, M22 and M52 showed great potential for being a plant growth promoter. Based on their 16S rRNA gene sequence analysis, M17, M22 and M52 were identified as Leclercia adecarboxylata, Margalitia shackletonii and Lysinibacillus pakistanensis, respectively.
Conclusion, significance and impact of study
Bacterial isolates exhibiting plant growth-promoting activities were successfully isolated from a biofertilizer and identified in this study. This finding provides an insight into the potential bacteria of a foliar fertilizer that may promote plant growth. Identification of these plant-growth promoters may help the scientists and agrochemical manufacturers to determine and disclose the key microorganisms of their biofertilizers, thereby contributing to the improvement of biofertilizers and promoting them as reliable alternatives to chemical fertilizers.
Bacteria--isolation &
;
purification
;
Fertilizers--microbiology


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