1.Clinical and Laboratory Characteristics of Streptococcus mitis Causing Bloodstream Infection in Children with Hematological Disease.
Yu-Long FAN ; Guo-Qing ZHU ; Zhi-Ying TIAN ; Yan-Xia LYU ; Zhao WANG ; Ye GUO ; Wen-Yu YANG ; Qing-Song LIN ; Xiao-Juan CHEN
Journal of Experimental Hematology 2025;33(1):286-291
OBJECTIVE:
To investigate the risk factors, clinical characteristics, and bacterial resistance of bloodstream infections caused by Streptococcus mitis in children with hematological disease, so as to provide a reference for infection control.
METHODS:
The clinical information and laboratory findings of pediatric patients complicated with blood cultures positive for Streptococcus mitis from January 2018 to December 2020 in the Institute of Hematology & Blood Diseases Hospital were searched and collected. The clinical characteristics, susceptibility factors, and antibiotic resistance of the children were retrospectively analyzed.
RESULTS:
Data analysis from 2018 to 2020 showed that the proportion of Streptococcus mitis isolated from bloodstream infections in children (≤14 years old) with hematological diseases was the highest (19.91%) and significantly higher than other bacteria, accounting for 38.64% of Gram-positive cocci, and presented as an increasing trend year by year. A total of 427 children tested positive blood cultures, including 85 children with bloodstream infections caused by Streptococcus mitis who tested after fever. Most children experienced a recurrent high fever in the early and middle stages (≤6 d) of neutropenia and persistent fever for more than 3 days. After adjusting the antibiotics according to the preliminary drug susceptibility results, the body temperature of most children (63.5%) returned to normal within 4 days. The 85 children were mainly diagnosed with acute myeloid leukemia (AML), accounting for 84.7%. The proportion of children in the neutropenia stage was 97.7%. The incidence of oral mucosal damage, lung infection, and gastrointestinal injury symptoms was 40%, 31.8%, and 27.1%, respectively. The ratio of elevated C-reactive protein (CRP) and procalcitonin was 65.9% and 9.4%, respectively. All isolated strains of Streptococcus mitis were not resistant to vancomycin and linezolid, and the resistance rate to penicillin, cefotaxime, levofloxacin, and quinupristin-dalfopristin was 10.6%, 8.2%, 9.4%, and 14.1%, respectively. None of children died due to bloodstream infection caused by Streptococcus mitis.
CONCLUSION
The infection rate of Streptococcus mitis is increasing year by year in children with hematological diseases, especially in children with AML. Among them, neutropenia and oral mucosal damage after chemotherapy are high-risk infection factors. The common clinical symptoms include persistent high fever, oral mucosal damage, and elevated CRP. Penicillin and cephalosporins have good sensitivity. Linezolid, as a highly sensitive antibiotic, can effectively control infection and shorten the course of disease.
Humans
;
Child
;
Streptococcal Infections/microbiology*
;
Retrospective Studies
;
Hematologic Diseases/complications*
;
Streptococcus mitis
;
Drug Resistance, Bacterial
;
Risk Factors
;
Microbial Sensitivity Tests
;
Anti-Bacterial Agents
;
Female
;
Male
;
Bacteremia/microbiology*
;
Child, Preschool
;
Adolescent
2.Antimicrobial consumption and resistance of restricted antibiotics in a Level III government hospital.
Mary Anne Abeleda ; Imelda Peñ ; a ; Roderick Salenga ; Francis Capule ; Shiela Mae Nacabu-an ; Pamela Nala
Acta Medica Philippina 2024;58(16):68-76
OBJECTIVES
The objectives of the study were to determine the antibiotic consumption of restricted antibiotics and to correlate this with resistance rate.
METHODSA retrospective review of pharmacy dispensing records was conducted in the adult internal medicine wards of a tertiary level teaching hospital in the Philippines between March 2019 to February 2020. Antibiotic consumption was determined using Defined Daily Dose (DDD) per 1000 patient-days (PD). Correlations between antibiotic consumption and antibiotic resistance of restricted antibiotics were done. Outcomes were compared between Ward 1 (with the presence of a unit-dose pharmacist) and Ward 3 (without a unit-dose pharmacist).
RESULTSBoth wards showed decreasing trends of piperacillin-tazobactam consumption and increasing trends of ceftazidime consumption from quarter 1 to quarter 4. It was observed that levofloxacin was the most prescribed fluoroquinolone with the highest consumption recorded from March to May 2019 in Ward 3 of 350.2 DDD/1000 PD as compared with ciprofloxacin which has the highest consumption (23.3 DDD/1000 PD) during the period June to August 2019 in Ward 1. Antibiotic resistance of Acinetobacter baumannii against ciprofloxacin, levofloxacin, and piperacillin-tazobactam were statistically significantly different between the wards. In Ward 1, ciprofloxacin consumption was strongly positively correlated with Escherichia coli resistance (r = 0.90). In Ward 3, a significantly moderately positive association was observed for ceftazidime consumption and A. baumannii resistance (r = 0.61), positive correlation between piperacillin-tazobactam and E. coli resistance (r = 0.65), and a strong positive correlation in Ward 3 between levofloxacin and Pseudomonas aeruginosa resistance (r = 0.71).
CONCLUSIONThe restriction and pre-authorization strategy of the AMS program has greatly contributed to the decrease in the consumption of almost all restricted antibiotics. This strategy has been helpful in minimizing unnecessary antibiotic use associated with inappropriate drug therapy. The success of the AMS program has been based on the collective efforts of the AMS team with the implementation of hospital policies, such as the AMS program, across the different sites in the hospital in order to achieve optimum patient health outcomes. It was noted that the resistance rates of A. baumannii against ciprofloxacin, levofloxacin, and piperacillin-tazobactam were higher in Ward 3 compared to Ward 1 which makes infections very difficult to treat which may result to prolonged hospital stay, increased health-care costs and increased mortality rate. This study has supported the involvement of pharmacists in the AMS team by conducting auditing activities that promote safe compliance of restricted antibiotic use among patients. Pharmacists can greatly participate on either prospective or retrospective review of antibiotic utilization and analyze trends of antibiotic consumption data to provide feedback to prescribing physicians on prescribing patterns and possible correlation with occurrence of antibiotic resistance.
Antibiotic Resistance ; Drug Resistance, Microbial
3.A single-center retrospective study of pathogen distribution and antibiotic resistance of bloodstream infections in emergency department.
Yishu TANG ; Lihua CHEN ; Jie XIAO ; Kun YAN ; Jing QI ; Kefu ZHOU ; Huaizheng LIU
Journal of Central South University(Medical Sciences) 2024;49(11):1799-1807
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*
4.Clinical features and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen.
Cai Hong WANG ; Mei Lian HUANG ; Zhi Qiang ZHUO ; Zi Xuan WANG ; Lei CHEN ; Yi Qing SONG ; Hui YU
Chinese Journal of Pediatrics 2023;61(8):685-689
Objective: To investigate the clinical characteristics, serogroups and antimicrobial resistance of invasive non-typhoid Salmonella infection in children at Xiamen. Methods: Retrospective cohort study. The clinical manifestations, treatment, prognosis, serogroups and antimicrobial resistance of 29 hospitalized children with invasive non-typhoid Salmonella infection confirmed by blood, cerebrospinal fluid, bone marrow and other sterile body fluids or deep pus culture at the Department of Infectious Diseases, the Department of Orthopedics and the Department of General Surgery in Xiamen Children's Hospital from January 2016 to December 2021 were analyzed. According to the clinical diagnosis criteria, the patients were divided into sepsis group and non-sepsis group (bacteremia and local suppurative infection). The inflammatory markers, serogroups distribution and drug resistance were compared between the two groups. Comparison between groups using Mann-Whitney U test and χ2 test. Results: Among the 29 cases, there were 17 males and 12 females, with an onset age of 14 (9, 25) months, and 10 cases (34%) of patients were younger than 1 year old, 15 cases (52%) under 1 to 3 years old, and 4 cases (14%) greater than or equal 3 years old. The onset time of 25 cases (86%) was from April to September. The diseases included 19 cases (66%) septicemia (2 of which were combined with suppurative meningitis), 10 cases (34%) non-sepsis group, including 7 cases bacteremia and 3 cases local suppurative infection (2 cases of osteomyelitis, 1 case of appendicitis with peritonitis). The clinical manifestations were fever in 29 cases (100%), diarrhea and abdominal pain in 18 cases (62%), cough and runny nose in 10 cases (34%). Eighteen cases (62%) were cured and 11 cases (38%) were improved by effective antibiotics treatment. C-reactive protein in sepsis group was significantly higher than that in non-sepsis group (25.2 (16.1, 56.4) vs. 3.4 (0.5, 7.5) mg/L, Z=-3.81, P<0.001).The serogroups of C, B and E were the most prevalent among non-typhoid Salmonella isolates, accounting for 10 cases (34%), 9 cases (31%) and 7 cases (24%) respectively. Antibacterial drug sensitivity test showed that the sensitivity rates of imipenem, ertapenem and piperaciratazobactam were all 100% (31/31), those of ceftazidime, ceftriaxone, and cefepime were 94% (29/31), 94% (29/31) and 97% (30/31) respectively. The drug resistance rates of ampicillin, ampicillin-sulbactam and trimethoprim-sulfamethoxazole were 51% (16/31), 48% (15/31) and 48% (15/31) respectively, those of cefazolin, cefotetan, tobramycin, gentamicin and amikacinwere all 100% (31/31). There were no significant differences in the drug resistance rates of ceftazidime, ceftriaxone, aztreonam, ampicillin-sulbactam, ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin between the sepsis group and the non-sepsis group (χ2=0.31,0.31,0.00,0.02,0.02,0.02,0.26, all P>0.05). Conclusions: Invasive non-typhoid Salmonella infection in children at Xiamen mainly occurred in infants younger than 3 years old.The main clinical manifestations are fever, abdominal pain and diarrhea. C-reactive protein can be served as the laboratory indicators for indicating sepsis. The third generation of cephalosporins is recommended as the first choice for treatment.
Infant
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Male
;
Female
;
Child
;
Humans
;
Child, Preschool
;
Anti-Bacterial Agents/therapeutic use*
;
Ceftriaxone/therapeutic use*
;
Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use*
;
Ceftazidime/therapeutic use*
;
Retrospective Studies
;
C-Reactive Protein
;
Drug Resistance, Bacterial
;
Salmonella Infections/microbiology*
;
Ampicillin/therapeutic use*
;
Salmonella
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Diarrhea/drug therapy*
;
Bacteremia
;
Abdominal Pain
;
Microbial Sensitivity Tests
5.Clinical features of post-neurosurgical bacterial meningitis in children.
Li Juan LUO ; Jing WANG ; Wen Juan CHEN ; Ya Juan ZHOU ; Yuan Jie ZHOU ; Yun Hai SONG ; Nan SHEN ; Qing CAO
Chinese Journal of Pediatrics 2023;61(8):690-694
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.
Male
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Female
;
Humans
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Child
;
China/epidemiology*
;
Anti-Bacterial Agents/pharmacology*
;
Meningitis, Bacterial/diagnosis*
;
Gram-Negative Bacterial Infections/drug therapy*
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Gram-Positive Bacteria
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Gram-Positive Bacterial Infections/drug therapy*
;
Carbapenems
;
Retrospective Studies
;
Microbial Sensitivity Tests
;
Drug Resistance, Bacterial
6.Clinical and etiological characteristics of infectious vulvovaginitis in children in Zhejiang province from 2009 to 2019.
Hui Hui GAO ; Sun Yi WANG ; Yu Chen ZHANG ; Ming Ming ZHOU ; Chun Zhen HUA ; Chang Zheng YUAN ; Li Ying SUN
Chinese Journal of Pediatrics 2023;61(11):1024-1030
Objective: To explore the clinical characteristics, common pathogens in children with vulvovaginitis. Methods: This was a retrospective cases study. A total of 3 268 children with vulvovaginitis were enrolled, who visited the Department of Pediatric and Adolescent Gynecology, Children's Hospital, Zhejiang University School of Medicine from January 2009 to December 2019. Patients were divided into 3 groups according to the age of <7, 7-<10 and 10-18 years. Patients were also divided in to 4 groups according to the season of first visit. The pathogen distribution characteristics of infective vulvovaginitis were compared between the groups. Their clinical data were collected and then analyzed by χ2 test. Results: The were 3 268 girls aged (6.2±2.5) years. There were 1 728 cases (52.9%) aged <7 years, 875 cases (26.8%) aged 7-<10 years, and 665 cases (20.3%) aged 10-18 years. Of these cases, 2 253 cases (68.9%) were bacterial vulvovaginitis, 715 cases (21.9%) were fungal vulvovaginitis and 300 cases (9.2%) were vulvovaginitis infected with other pathogens. Bacterial culture of vaginal secretions was performed in 2 287 cases, and 2 287 strains (70.0%) of pathogens were detected, of which the top 5 pathogens were Streptococcus pyogenes (745 strains, 32.6%), Haemophilus influenzae (717 strains, 31.4%), Escherichia coli (292 strains, 12.8%), Staphylococcus aureus (222 strains, 9.7%) and Klebsiella pneumoniae (67 strains, 2.9%). Regarding different age groups, H.influenzae was the most common in children under 7 years of age (40.3%, 509/1 263), S.pyogenes (41.9%, 356/849) was predominantly in children aged 7 to 10 years, and E.coli was predominant in children aged 10 to 18 years (26.3%, 46/175). Susceptibility results showed that S.pyogenes was susceptible to penicillin G (610/610, 100.0%), ceftriaxone (525/525, 100.0%), and vancomycin (610/610, 100.0%); the resistance rates to erythromycin and clindamycin were 91.9% (501/545)and 90.7% (495/546), respectively. For H.influenzae, 32.5% (161/496) produced β-elactamase, and all strains were sensitive to meropenem (489/489, 100.0%) and levofloxacin (388/388, 100.0%), while 40.5% (202/499) were resistant to ampicillin. Among E.coli, all strains were sensitive to imipenem(100%, 175/175). The resistance rates of E.coli to levofloxacin and ceftriaxone were 29.1% (43/148) and 35.1% (59/168), respectively. A total of 48 strains of methicillin-resistant Staphylococcus aureus (MRSA) were isolated with a proportion of 28.3% (45/159) in 3 268 patients. The results of drug susceptibility test showed that all MRSA strains were sensitive to linezolid 100.0% (40/40), vancomycin (45/45, 100.0%), and tigecycline (36/36, 100.0%); the resistance rates of MRSA to penicillin G, erythromycin and clindamycin were 100% (45/45), 95.6% (43/45) and 88.9% (40/45), respectively. All methicillin-sensitive Staphylococcus aureus (MSSA) strains were sensitive to oxacillin (114/114, 100.0%), linezolid (94/94, 100.0%), vancomycin (114/114, 100.0%), and tigecycline (84/84, 100.0%); it's resistance rates to penicillin G, erythromycin and clindamycin were 78.1% (89/114), 59.7% (68/114) and 46.5% (53/114), respectively. The drug resistance rate of MSSA to penicillin G, erythromycin and clindamycin were lower than those of MRSA (χ²=11.71,19.74,23.95, respectively, all P<0.001). Conclusions: The age of consultation for pediatric infectious vulvovaginitis is mainly around 6 years. The most common pathogens are S.pyogenes, H.influenzae and Escherichia coli. Third generation cephalosporins can be used as the first choice of empirical anti-infection drugs. However, the results of drug susceptibility should be considered for targeted treatment.
Female
;
Adolescent
;
Child
;
Humans
;
Anti-Bacterial Agents/therapeutic use*
;
Vancomycin/therapeutic use*
;
Methicillin-Resistant Staphylococcus aureus
;
Clindamycin/therapeutic use*
;
Ceftriaxone/therapeutic use*
;
Tigecycline/therapeutic use*
;
Linezolid/therapeutic use*
;
Levofloxacin/therapeutic use*
;
Retrospective Studies
;
Microbial Sensitivity Tests
;
Staphylococcus aureus
;
Staphylococcal Infections/drug therapy*
;
Erythromycin/therapeutic use*
;
Methicillin
;
Penicillin G/therapeutic use*
;
Escherichia coli
;
Drug Resistance, Bacterial
7.Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020.
Yu Jie HU ; Yang XIAO ; Shuang Jia DONG ; Jian Yun ZHAO ; Hui LI ; Da Jin YANG ; Yin Ping DONG ; Jin XU ; Feng Qin LI
Chinese Journal of Preventive Medicine 2023;57(4):557-565
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.
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
8.Study of the urban-impact on microbial communities and their virulence factors and antibiotic resistance genomes in the Nandu River, Haikou.
Yu Feng FAN ; Zhen Peng LI ; Xiao Jie YU ; Zhe LI ; Hai Jian ZHOU ; Ya Lin ZHANG ; Xiao Ting GAN ; De HUA ; Xin LU ; Biao KAN
Chinese Journal of Epidemiology 2023;44(6):974-981
Objective: To explore the changes in bacterial community structure, antibiotic resistance genome, and pathogen virulence genome in river water before and after the river flowing through Haikou City and their transmission and dispersal patterns and to reveal anthropogenic disturbance's effects on microorganisms and resistance genes in the aquatic environment. Methods: The Nandu River was divided into three study areas: the front, middle and rear sections from the upstream before it flowed through Haikou City to the estuary. Three sampling sites were selected in each area, and six copies of the sample were collected in parallel at each site and mixed for 3 L per sample. Microbial community structure, antibiotic resistance, virulence factors, and mobile genetic elements were analyzed through bioinformatic data obtained by metagenomic sequencing and full-length sequencing of 16S rRNA genes. Variations in the distribution of bacterial communities between samples and correlation of transmission patterns were analyzed by principal co-ordinates analysis, procrustes analysis, and Mantel test. Results: As the river flowed through Haikou City, microbes' alpha diversity gradually decreased. Among them, Proteobacteria dominates in the bacterial community in the front, middle, and rear sections, and the relative abundance of Proteobacteria in the middle and rear sections was higher than that in the front segment. The diversity and abundance of antibiotic resistance genes, virulence factors, and mobile genetic elements were all at low levels in the front section and all increased significantly after flow through Haikou City. At the same time, horizontal transmission mediated by mobile genetic elements played a more significant role in the spread of antibiotic-resistance genes and virulence factors. Conclusions: Urbanization significantly impacts river bacteria and the resistance genes, virulence factors, and mobile genetic elements they carry. The Nandu River in Haikou flows through the city, receiving antibiotic-resistant and pathogen-associated bacteria excreted by the population. In contrast, antibiotic-resistant genes and virulence factors are enriched in bacteria, which indicates a threat to environmental health and public health. Comparison of river microbiomes and antibiotic resistance genomes before and after flow through cities is a valuable early warning indicator for monitoring the spread of antibiotic resistance.
Humans
;
Rivers
;
Virulence Factors/genetics*
;
RNA, Ribosomal, 16S/genetics*
;
Microbiota/genetics*
;
Anti-Bacterial Agents
;
Drug Resistance, Microbial/genetics*
9.Molecular epidemiology and antibiotic resistance of Pseudomonas aeruginosa isolated from blood in a hospital in Shandong Province from 2014 to 2021.
Jia Zheng WANG ; Xiu Tao DONG ; Xiao Ning ZHANG ; Piao DENG ; Fang CHENG ; Wan Shan MA
Chinese Journal of Preventive Medicine 2023;57(10):1558-1564
Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.
Humans
;
Pseudomonas aeruginosa/genetics*
;
Multilocus Sequence Typing
;
Molecular Epidemiology
;
Pseudomonas Infections/microbiology*
;
Microbial Sensitivity Tests
;
Hospitals
;
Carbapenems/pharmacology*
;
Drug Resistance, Multiple, Bacterial/genetics*
;
Anti-Bacterial Agents/pharmacology*
;
beta-Lactamases
10.Molecular epidemiology and antibiotic resistance of Pseudomonas aeruginosa isolated from blood in a hospital in Shandong Province from 2014 to 2021.
Jia Zheng WANG ; Xiu Tao DONG ; Xiao Ning ZHANG ; Piao DENG ; Fang CHENG ; Wan Shan MA
Chinese Journal of Preventive Medicine 2023;57(10):1558-1564
Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.
Humans
;
Pseudomonas aeruginosa/genetics*
;
Multilocus Sequence Typing
;
Molecular Epidemiology
;
Pseudomonas Infections/microbiology*
;
Microbial Sensitivity Tests
;
Hospitals
;
Carbapenems/pharmacology*
;
Drug Resistance, Multiple, Bacterial/genetics*
;
Anti-Bacterial Agents/pharmacology*
;
beta-Lactamases


Result Analysis
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