Humans ; Bacteremia ; Cross Infection ; Methicillin-Resistant Staphylococcus aureus ; Retrospective Studies ; Sepsis ; Staphylococcal Infections/epidemiology* ; Staphylococcus aureus ; Tertiary Care Centers ; China

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.
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

Humans ; Escherichia coli ; Klebsiella pneumoniae ; Retrospective Studies ; Hospitals, General ; Singapore/epidemiology* ; Escherichia coli Infections/epidemiology* ; Sepsis/drug therapy* ; beta-Lactamases ; Anti-Bacterial Agents/therapeutic use* ; Bacteremia/drug therapy* ; Microbial Sensitivity Tests

OBJECTIVE: To analyze the clinical characteristics of bloodstream infection (BSI) in patients treated by hematopoietic stem cell transplantation (HSCT). METHODS: The clinical characteristics, distribution of pathogenic bacteria causing BSI and drug sensitivity of 910 patients treated by HSCT in our department from January 2013 to June 2020 were retrospectively analyzed. RESULTS: Among 910 HSCT patients, 111 patients were diagnosed as BSI within 100 days after transplantation, and 98 patients showed BSI during the period of agranulocytosis. Multivariate analysis showed that the usage of anti-thymocyte globulin (ATG), long duration of agranulocytosis and low infusion volume of mononuclear cell (MNC) were the independent risk factors affecting BSI after HSCT. Among 121 pathogenic bacteria isolated, 76 Gram-negative (G^-) bacteria (62.8%), 40 Gram-positive (G⁺) bacteria (33.0%), and 5 fungi (4.1%) were detected out. The top three pathogens were Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa. The drug-resistance rates of Escherichia coli and Klebsiella pneumoniae to carbapenems was 14.3% and 7.7%, respectively, and Pseudomonas aeruginosa was 66.7%. The susceptibility of G⁺ bacteria to vancomycin, linezolid and teicoplanin was 97.5%, 100% and 100%, respectively. The crude mortality rate of the patients with BSI at 100 days after HSCT was significantly higher than that of patients without BSI (P<0.001). CONCLUSION The usage of ATG, long duration of agranulocytosis and low infusion volume of MNC are independent risk factors for BSI after HSCT. The pathogens after HSCT are mainly G- bacteria. Pseudomonas aeruginosa is highly resistant to carbapenems. Key words　　;
Bacteremia/epidemiology* ; Bacteria ; Hematopoietic Stem Cell Transplantation ; Humans ; Retrospective Studies ; Sepsis

PURPOSE: We aimed to investigate the epidemiological characteristics of Staphylococcus aureus bacteremia in Korean children. METHODS: We retrospectively collected and analyzed data from the medical records of the patients with S. aureus bacteremia ≤18 years of age in Gil Medical Center from 2002 to 2016. RESULTS: A total of 212 SAB cases were detected. The annual incidence of SAB from 2002 to 2016 ranged from 0.77 to 1.95 per 1,000 patients hospitalized. The neonate group (<28 days of age) and the pediatric group (28–18 years of age) were 51.4% (n=109) and 48.6% (n=103), respectively. According to the origin of infection, there were 93 cases (43.9%) of community-associated (CA)-SAB and 119 cases (56.1%) of healthcare-associated (HA)-SAB. The rates of HA-SAB among the neonate group and among the pediatric group were 64.2% and 47.6%, respectively (P=0.015). There was no difference in complications between CA-SAB and HA-SAB, but mortality was higher in HA-SAB. The proportion of methicillin-resistance S. aureus (MRSA) was the highest in neonates (88.1%), decreased with age, and was 36.4%–37.5% among children aged ≥5 years. The MRSA proportion was 72.2%, showing no consistent trend over the period. CONCLUSIONS: The annual incidence of SAB and the proportion of MRSA in SAB remained constant in the recent 15 years in children. Judicious decision of antimicrobial agents for treatment considering the patient's age and the origin of infection is necessary.
Anti-Infective Agents ; Bacteremia ; Child ; Epidemiology ; Humans ; Incidence ; Infant ; Infant, Newborn ; Medical Records ; Methicillin-Resistant Staphylococcus aureus ; Mortality ; Retrospective Studies ; Staphylococcus aureus ; Staphylococcus

OBJECTIVE: To investigate the phylogenetics and prevalence of bloodstream infections with ST131, the antimicrobial resistance profiles of the pathogens, and the clinical features. METHODS: Non-duplicate isolates were collected from 144 patients with bloodstream infections in our hospital between January and December, 2016.The phylogenetic groups of the isolates were analyzed using multiplex PCR, and O serotyping of ST131 strains was performed by allele-specific PCR.The clinical characteristics of the 144 patients were analyzed to define the differences in the clinical features between patients with ST131 infection and those with non-ST131 infection.Antibiotic susceptibility of the isolates was determined using the Vitek 2 compact system. RESULTS: The phylogenetic group analysis showed a domination by group B2 (41.0%[59/144]), followed by group F, group B1 and group E, which accounted for 16.7%(24/144), 13.9%(20/144), and 13.2% (19/144), respectively.Nine strains (6.3%) of were identified to be ST131 strains, among which 8 were O25b-B2-ST131 strains and 1 was O16-B2-ST131 strain.Of the 9 cases of ST131 infection, 7(77.8%) were found to occur in a nosocomial setting.The demographic characteristics and clinical features of the ST131-infected patients were similar to those of non-ST131-infected patients.ST131 strains were sensitive to piperacillin/tazobactam, imipenem, ertapenem, and amikacin, but showed high resistance rates to cefazolin, ceftriaxone, ciprofloxacin, levofloxacin, gentamicin, and trimethoprim/ sulfamethoxazole (all over 50%).The positivity rate of ESBLs in the ST131 strains was 77.8%, and the multidrug resistance rate reached 88.9%, which was higher than that of non-ST131 isolates, but the difference was not statistically significant. CONCLUSIONS The most common phylogenetic groups of isolates from patients with bloodstream infections are group B2 and F, and the positivity rate of ST131 is low.We for the first time detected O16-ST131 in patients with blood-borne infections in China.The clinical features of ST131-infected patients are similar to those of non-ST131-infected patients.The positivity rate of ESBLs and the multidrug resistance rate are high in ST131 strains, which may raise concerns in the future.
Anti-Bacterial Agents ; therapeutic use ; Bacteremia ; drug therapy ; epidemiology ; microbiology ; China ; Drug Resistance, Bacterial ; Escherichia coli ; classification ; drug effects ; genetics ; Escherichia coli Infections ; drug therapy ; epidemiology ; microbiology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Phylogeny ; Species Specificity

Escherichia coli can harbor genomic pks islands that code for a polyketide-peptide genotoxin known as colibactin. E. coli strains carrying pks islands trigger genetic instability. pks islands have been significantly associated with bacteremia. We investigated the molecular epidemiology of bacteremic E. coli isolates and the prevalence of bacteremia-causing E. coli carrying pks islands. A total of 146 E. coli isolates were collected at a tertiary-care hospital from January 2015 to December 2016. The phylogenetic groups were determined by multiplex PCR. All isolates were screened by PCR for sequence type 131 (ST131)-associated single-nucleotide polymorphisms (SNPs) in mdh and gyrB. For detection of pks islands, we performed PCR for the clbB and clbN genes as colibactin system markers. Phylogenetic group B2 was the most common, accounting for 54.1% (N=79) of the isolates, followed by group D with 29.5% (N=43), group A with 11.6% (N=17), and group B1 with 4.8%. Of the group B2 isolates, 40.5% were ST131 strains and 32.9% carried pks islands. Only three ST131 isolates in group B2 carried the clbB and clbN genes, while the other 23 ST131 isolates did not. The pks gene might not be associated with ST131 strains.
Bacteremia* ; Escherichia coli* ; Escherichia* ; Humans ; Islands* ; Molecular Epidemiology ; Multiplex Polymerase Chain Reaction ; Polymerase Chain Reaction ; Prevalence*

BACKGROUND: Invasive bacterial infections in apparently immunocompetent children were retrospectively analyzed to figure causative bacterial organisms in Korea. METHODS: A total of 947 cases from 25 university hospitals were identified from 2006 to 2010 as a continuance of a previous 10-year period study from 1996 to 2005. RESULTS: Escherichia coli (41.3%), Streptococcus agalactiae (27.7%), and Staphylococcus aureus (27.1%) were the most common pathogens in infants < 3 months of age. S. agalactiae was the most prevalent cause of meningitis and pneumonia and E. coli was the major cause of bacteremia without localizing signs in this group. In children 3 to 59 months of age, Streptococcus pneumoniae (54.2%), S. aureus (20.5%), and Salmonella spp. (14.4%) were the most common pathogens. S. pneumoniae was the leading cause of pneumonia (86.0%), meningitis (65.0%), and bacteremia without localizing signs (49.0%) in this group. In children ≥ 5 years of age, S. aureus (62.8%) was the predominant pathogen, followed by Salmonella species (12.4%) and S. pneumoniae (11.5%). Salmonella species (43.0%) was the most common cause of bacteremia without localizing signs in this group. The relative proportion of S. aureus increased significantly over the 15-year period (1996–2010) in children ≥ 3 months of age (P < 0.001), while that of Haemophilus influenzae decreased significantly in both < 3 months of age group (P = 0.036) and ≥ 3 months of age groups (P < 0.001). CONCLUSION: S. agalactiae, E. coli, S. pneumoniae, and S. aureus are common etiologic agents of invasive bacterial infections in Korean children.
Bacteremia ; Bacterial Infections ; Child ; Epidemiology ; Escherichia coli ; Haemophilus influenzae ; Hospitals, University ; Humans ; Infant ; Korea ; Meningitis ; Pneumonia ; Retrospective Studies ; Salmonella ; Staphylococcus aureus ; Streptococcus agalactiae ; Streptococcus pneumoniae

PURPOSE: This study was aimed at analyzing the serotypes of group B streptococcus (GBS) isolated from Korean infants with invasive disease and evaluating their association with disease manifestation. METHODS: Data were retrospectively collected from invasive GBS infections at Gachon University Gil Medical Center from January 2006 to June 2012 and at Samsung Medical Center from April 2010 to November 2012. Serotypes were determined by slide agglutination test. RESULTS: A total of 37 cases were identified, which included 22 full-term infants and 15 preterm infants. Fifteen cases (40.5%) were early-onset, 19 (51.4%) was late-onset, and three (8.1%) was very late-onset. Early-onset diseases among preterm infants were higher than those among full-term infants (60.0% [9/15] vs. 27.3% [6/22], P =0.17). The most common manifestation was bacteremia (70.3%), followed by meningitis and septic arthritis. Among 24 isolates retrievable for serotyping, serotype III (41.7%) was most common, followed by V (16.7%), Ia, Ib, and II (12.5%, respectively), and non-typeable (4.2%). Serotype III was more common in isolates from full-term infants (10/22) than from preterm infants (0/15), whereas serotype V was more common in isolates from preterm infants (4/15) than from full-term infants (0/22) (P =0.002). No penicillin-resistant strain was detected, and resistance to erythromycin and clindamycin were both 64.9%. CONCLUSIONS: GBS is an important pathogen in both preterm and full-term infants, and serotype distribution of GBS causing invasive diseases can differ between preterm and full-term infants. It is necessary to monitor the nationwide epidemiology of GBS diseases, including in preterm infants, in order to prepare preventive measures without underestimating early-onset diseases.
Agglutination Tests ; Arthritis, Infectious ; Bacteremia ; Clindamycin ; Epidemiology ; Erythromycin ; Hospitals, University* ; Humans ; Infant* ; Infant, Newborn ; Infant, Premature ; Korea* ; Meningitis ; Retrospective Studies ; Serogroup* ; Serotyping ; Streptococcus ; Streptococcus agalactiae

The incidence and mortality of infective endocarditis (IE) in patients with severe burn remain high, which are attributed to invasive procedures, bacteremia, and wound infection after burns. Clinical clues for IE in burns are usually masked by burn-related manifestations, so the diagnosis of IE may be delayed or missed. For burned patients with persistent bacteremia of unknown source, especially Staphylococcus aureus-induced bacteremia, the diagnosis of IE should be considered according to the Duke criteria, and early echocardiography performance is particularly important. Antibiotic therapy is the mainstay initial management, and early surgical intervention is strongly recommended once IE is clearly diagnosed in patients with burns. In order to lower the incidence and mortality of IE in burns, it is very important to take prophylactic procedures along with the whole course of burn management.
Bacteremia ; epidemiology ; Burn Units ; Burns ; complications ; mortality ; surgery ; Endocarditis, Bacterial ; complications ; diagnosis ; microbiology ; mortality ; Humans ; Incidence ; Severity of Illness Index ; Staphylococcal Infections ; complications ; diagnosis ; Staphylococcus aureus ; isolation & purification ; Surgery, Plastic ; Wound Infection ; etiology ; mortality