Petroleum hydrocarbon pollution has become one of the global environmental problems, posing a serious threat to the environment and human health. Microbial remediation plays an important role in the remediation of petroleum hydrocarbon-contaminated environment. Nevertheless, the stress factors present in the environment polluted by petroleum hydrocarbons limit the effectiveness of microbial remediation. This paper reviews the common stress factors in petroleum hydrocarbon-polluted environment and the response mechanisms of microorganisms to these factors. Furthermore, we introduce the methods to improve microbial tolerance, such as irrational modification, rational modification based on systems biology tools or tolerance mechanisms, and the construction of microbial consortia. The application of these methods is expected to improve the viability and remediation efficiency of microorganisms in petroleum hydrocarbon-contaminated environment and provide new perspectives and technical support for environmental remediation.
Biodegradation, Environmental ; Petroleum/metabolism* ; Hydrocarbons/isolation & purification* ; Bacteria/genetics* ; Environmental Pollutants/isolation & purification* ; Petroleum Pollution

Mercury (Hg)-contaminated soil poses a significant threat to the environment and human health. Hg-resistant microorganisms have the ability to survive under the stress of inorganic and organic Hg and effectively reduce Hg levels and toxicity. Compared to physical and chemical remediation methods, microbial remediation technologies have garnered increasing attention in recent years due to their lower cost, remarkable efficacy, and minimal environmental impact. This paper systematically elucidates the molecular mechanisms of Hg resistance in microbes, with a focus on their potential applications in phytoremediation of Hg-contaminated soils through plant-microbe interactions. Furthermore, it highlights the critical role of microbes in enhancing the effectiveness of transgenic plants for Hg remediation, aiming to provide a theoretical foundation and scientific basis for the bioremediation of Hg-contaminated soils.
Mercury/toxicity* ; Biodegradation, Environmental ; Soil Pollutants/isolation & purification* ; Soil Microbiology ; Plants, Genetically Modified/metabolism* ; Bacteria/genetics*

Microbial denitrification is a major pathway for nitrogen removal from water bodies. However, denitrification is often difficult to continue when there is a lack of microbially available organic matter in the water body to serve as electron donors. In recent years, studies have shown that some denitrifying bacteria can directly utilize photoelectrons generated by sunlight-excited semiconductor minerals or natural organic matter for denitrification without the need for bioavailable organic matter as electron donors. This process is defined as microbial photoelectrotrophic denitrification. The discovery of microbial photoelectrotrophic denitrification phenomenon reshapes the previous knowledge about the chemoheterotrophic mode of denitrifying bacteria and broadens the pathway of nitrogen removal by the new photoelectrotrophic metabolism, which is of great significance to our understanding and exploration of sunlight-driven nitrogen cycling process. In this paper, we comprehensively sort out the existing research reports in the field of microbial photoelectrotrophic denitrification, systematically summarize the principle and the current research progress of microbial photoelectrotrophic denitrification, deeply analyze the problems and challenges faced by this technology, and make an outlook on the future research directions and application prospects of this technology, providing a reference for the further research and application of this technology.
Denitrification/physiology* ; Nitrogen/isolation & purification* ; Bacteria/metabolism* ; Sunlight ; Phototrophic Processes

OBJECTIVES: Bloodstream infections in emergency patients have a high incidence, severe disease progression, and rapid deterioration. Early administration of appropriate antimicrobial agents is crucial for improving patient outcomes. This study aims to investigate the incidence, pathogen distribution, and antimicrobial resistance patterns of bloodstream infections in emergency patients, providing a reference for rational antibiotic use in clinical practice. METHODS: Medical records of patients diagnosed with bloodstream infections in the emergency department of a hospital in Hunan Province between January 2018 and October 2022 were retrospectively collected. Clinical characteristics of bloodstream infection patients were analyzed, and the distribution trends and antimicrobial susceptibility of clinical isolates were examined. RESULTS: During the study period, 2 215 blood culture samples were submitted from the emergency department, with a positivity rate of 13.27%. After excluding eight cases with missing data or suspected contamination, 286 patients with bloodstream infections were included, with community-acquired infections accounting for the majority (85.66%). The most common primary infection site was the urinary tract (24.48%), followed by respiratory tract infections (20.28%) and biliary and intra-abdominal infections (17.13%). The 30-day mortality rate of bloodstream infections was 16.08%. A total of 286 pathogens were isolated, including 181 (63.29%) Gram-negative bacteria, primarily Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa; 101 (35.31%) Gram-positive bacteria, mainly Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumoniae; and only 4 (1.40%) fungal isolates. Antimicrobial susceptibility testing showed that the key Enterobacteriaceae strains exhibited resistance rates of 2.4% to carbapenems, 16.3% to piperacillin sodium and tazobactam sodium, and 15.3% to ceftazidime, with no detected resistance to tigecycline or polymyxins. The main non-fermentative bacteria showed resistance rates of 29.6% to piperacillin sodium and tazobactam sodium, 13.3% to cefoperazone sodium and sulbactam sodium, and 27.1% to quinolones. Among Gram-negative bacteria, multidrug-resistant strains accounted for 40.9% (74/181), with carbapenem-resistant Escherichia coli and Klebsiella pneumoniae detected in 5.4% (5/92) and 13.6% (6/44) of cases, respectively. No carbapenem-resistant Pseudomonas aeruginosa was identified. Among Gram-positive bacteria, resistance rates to penicillin G, rifampicin, and cefoxitin were 74.7%, 4.2%, and 50%, respectively, with only 3 cases of resistant to glycopeptide antibiotics. CONCLUSIONS Bloodstream infections in emergency patients are predominantly community-acquired, with Gram-negative bacteria being the most common pathogens. The isolated pathogens exhibited relatively low resistance rates to commonly used clinical antibiotics.
Retrospective Studies ; Emergency Service, Hospital/statistics & numerical data* ; Drug Resistance, Bacterial ; Anti-Bacterial Agents/therapeutic use* ; Incidence ; Microbial Sensitivity Tests/statistics & numerical data* ; Bacteremia/microbiology* ; Community-Acquired Infections/microbiology* ; Gram-Negative Bacteria/isolation & purification* ; Blood Culture/statistics & numerical data* ; Humans ; Male ; Female ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; China/epidemiology*

Objective:To analyze the correlation between nasal mucosal microbiota diversity and the pathogenesis and prognosis of chronic sinusitis. Methods:A total of 80 patients with chronic sinusitis（CRS） admitted to Second Affiliated Hospital of Suzhou University were selected as the research group, and 80 patients with chronic dacryocystitis and nasal septum deviation without sinus inflammation admitted to our hospital during the same period were selected as the control group, nasal secretory specimens were collected under nasal endoscopic guidance by nasal swab, and matrix-assisted laser desorption ionization classification time mass spectrometry, anaerobic bacterial culture and common bacterial culture were performed to compare the differences in nasal mucosal flora between groups. Patients with chronic sinusitis were followed up for 6 months, and nasal secretions were collected again to detect microflora, and the patients were divided into relapse group（21 cases） and non-recurrence group（59 cases） according to whether the patients had relapse. Compare the diversity of nasal microbiota between groups. Results:There were no significant differences in mean relative abundance（MRA） between the two groups of preoperative phylum Microbacterium verrucobacterium, Cyanobacterium phylum, Phylum Laubia mlaus, Porphyromonas species, Enterococcus species, Fusobacterium species, Enterobacter species, Enterobacter species, Erythrobacterium species, Ralstonia species, Bacteroides and Streptococcus species（P>0.05）. The MRA of Acidobacterium, Proteobacteria, Actinomycetes MRA, Moraxia, Cyanobacterium, Corynebacterium and Staphylococcus were significantly lower than those of the control group（P<0.05）, and the MRA of Escher-Shigella species, Fusobacterium, Bacteroides, Firmicutes, Neisseria, Pseudomonas, Haemophilus and Lactobacillus was significantly higher than that of the control group（P<0.05）, and there was no significant difference in MRA at the level of nasal flora and genus before and after surgery in the relapsed group（P>0.05）. The MRA of Bacteroides after surgery was significantly lower in the non-recurrent group than that before surgery（P<0.05）, the MRA of Corynebacterium and Actinomycetes was higher significantly than that of preoperative（P<0.05）, and there was no significant difference in MRA of other species and phylum（P>0.05）. Conclusion:The onset of CRS is related to nasal mucosal dysbacteria, and whether the dysbacteriosis improves after surgery is correlated with the prognosis of patients.
Humans ; Chronic Disease ; Sinusitis/microbiology* ; Prognosis ; Nasal Mucosa/microbiology* ; Microbiota ; Male ; Female ; Middle Aged ; Adult ; Bacteria/isolation & purification*

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*

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

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Air Microbiology ; Bacteria/isolation & purification* ; Child ; Child, Preschool ; China/epidemiology* ; DNA, Bacterial/analysis* ; DNA, Ribosomal/analysis* ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Pneumonia, Bacterial/microbiology* ; Risk Assessment/methods* ; Young Adult

A multiplex PCR method was developed to detect the main pathogens of Qinghai Tibetan sheep endometritis. First, the genomes of five standard bacterial strains were extracted and specific primers were selected; the multiplex PCR method was established by using the genome of the standard strain as a template. The samples were collected by sterile cotton swab from Tibetan sheep uterus, and then placed in LB medium and numbered. After 48 h, the genomes of cultured bacteria were extracted and detected by single PCR method, then the positive samples were recorded. The positive samples detected by single PCR were selected for multiplex PCR detection and recorded again. The coincidence rate between these two methods was calculated to measure the accuracy of multiplex PCR. In order to identify the species of the pathogen, 30 positive samples verified by single and multiplex PCR were randomly selected for bacterial isolation and identification. In the 600 samples, the infected ratio of Streptococcus agalactiae (GBS) was 47.33%, Escherichia coli 34.83%, Staphylococcus aureus 6.5%, Salmonella and Trueperella pyogenes were negatively detected. Among the positive samples detected by multiplex PCR, the positive ratio of GBS was 45.50%, E. coli 33.50%, S. aureus 6.5%. Comparison of two detection results, Multiplex PCR detection coincidence rate is more than 95%. The isolated pathogens were identified as E. coli, GBS and S. aureus, which was consistent with the results of two methods. The multiplex PCR method was successfully established and the main pathogens of endometritis in Qinghai Tibetan sheep were GBS, E. coli and S. aureus.
Animals ; Bacteria ; genetics ; isolation & purification ; Bacteriological Techniques ; methods ; Endometritis ; microbiology ; veterinary ; Female ; Multiplex Polymerase Chain Reaction ; standards ; Polymerase Chain Reaction ; veterinary ; Sensitivity and Specificity ; Sheep ; Sheep Diseases ; microbiology ; Tibet

Objective: High PM concentration is the main feature of increasing haze in developing states, but information on its microbial composition remains very limited. This study aimed to determine the composition of microbiota in PM in Guangzhou, a city located in the tropics in China. Methods: In Guangzhou, from March 5 to 10 , 2016, PM was collected in middle volume air samplers for 23 h daily. The 16S rDNA V4 region of the PM sample extracted DNA was investigated using high-throughput sequence. Results: Among the Guangzhou samples, , , , , and were the dominant microbiota accounting for more than 90% of the total microbiota, and was the dominant gram-negative bacteria, accounting for 21.30%-23.57%. We examined the difference in bacterial distribution of PM between Beijing and Guangzhou at the genus level; was found in both studies, but was only detected in Guangzhou. Conclusion In conclusion, the diversity and specificity of microbial components in Guangzhou PM were studied, which may provide a basis for future pathogenicity research in the tropics.
Air Microbiology ; Air Pollutants ; analysis ; Bacteria ; classification ; isolation & purification ; China ; Cities ; Environmental Monitoring ; Microbiota ; Particle Size ; Particulate Matter ; analysis ; RNA, Bacterial ; analysis ; RNA, Ribosomal, 16S ; analysis