OBJECTIVE: To investigate the characteristics of gut microbiota changes in patients with acute myeloid leukemia (AML) undergoing induction chemotherapy and to explore the relationship between infectious complications and gut microbiota. METHODS: Fecal samples were collected from 37 newly diagnosed AML patients at four time points: before induction chemotherapy, during chemotherapy, during the neutropenic phase, and during the recovery phase. Metagenomic sequencing was used to analyze the dynamic changes in gut microbiota. Correlation analyses were conducted to assess the relationship between changes in gut microbiota and the occurrence of infectious complications. RESULTS: During chemotherapy, the gut microbiota α-diversity (Shannon index) of AML patients exhibited significant fluctuations. Specifically, the diversity decreased significantly during induction chemotherapy, further declined during the neutropenic phase (P < 0.05, compared to baseline), and gradually recovered during the recovery phase, though not fully returning to baseline levels.The abundances of beneficial bacteria, such as Firmicutes and Bacteroidetes, gradually decreased during chemotherapy, whereas the abundances of opportunistic pathogens, including Enterococcus, Klebsiella, and Escherichia coli, progressively increased.Analysis of the dynamic changes in gut microbiota of seven patients with bloodstream infections revealed that the bloodstream infection pathogens could be detected in the gut microbiota of the corresponding patients, with their abundance gradually increasing during the course of infection. This finding suggests that bloodstream infections may be associated with opportunistic pathogens originating from the gut microbiota.Compared to non-infected patients, the baseline samples of infected patients showed a significantly lower relative abundance of Bacteroidetes (P < 0.05). Regression analysis indicated that Bacteroidetes abundance is an independent predictive factor for infectious complications (P < 0.05, OR =13.143). CONCLUSION During induction chemotherapy in AML patients, gut microbiota α-diversity fluctuates significantly, and the abundance of opportunistic pathogens increase, which may be associated with bloodstream infections. Patients with lower baseline Bacteroidetes abundance are more prone to infections, and its abundance can serve as an independent predictor of infectious complications.
Humans ; Gastrointestinal Microbiome ; Leukemia, Myeloid, Acute/microbiology* ; Induction Chemotherapy ; Feces/microbiology* ; Male ; Female ; Middle Aged

OBJECTIVE: To investigate the clinical features, distribution of pathogenic bacteria, and drug resistance of bloodstream infection in children with acute leukemia. METHODS: Clinical data of 93 blood culture-positive children with acute leukemia from January 2015 to December 2019 in Department of Pediatrics, The Second Hospital of Anhui Medical University were analyzed retrospectively. RESULTS: In these 93 cases, 78 cases were in the period of neutrophil deficiency. There were 54 Gram-negative bacteria (G^-) (58.1%) found through blood culture, and the top 4 strains were Escherichia coli (15.1%), Klebsiella pneumoniae (13.9%), Pseudomonas aeruginosa (6.5%), and Enterobacter cloacae (6.5%). There were 39 Gram-positive bacteria (G⁺) (41.9%) detected, and the top 4 strains were Staphylococcus epidermidis (10.8%), Streptococcus pneumoniae (6.5%), Staphylococcus hemolyticus (5.4%), and Staphylococcus human (5.4%). Among 74 strains of pathogenic bacteria from acute lymphoblastic leukemia (ALL) children, there were 29 strains of G⁺ bacteria (39.2%) and 45 strains of G^- bacteria (60.8%). While in 19 strains from acute myeloblastic leukemia (AML) patients, G^- bacteria accounted for 47.4% and G⁺ bacteria accounted for 52.6%. In 15 ALL children without neutropenia, G⁺ bacteria made up the majority of the strains (66.7%). In the 93 strains of pathogenic bacteria, 13 (13.9%) strains were multidrug-resistant. Among them, extended-spectrum β-lactamases accounted for 42.9%, carbapenemase-resistant enzyme Klebsiella pneumoniae 15.4%, and carbapenemase-resistant enzyme Enterobacter cloacae strains 33.3%, which were detected from G^- bacteria. While, 13.3% of methicillin-resistant coagulase-negative Staphylococci accounted for 13.3% detected from G⁺ bacteria, but linezolid, vancomycin, teicoplanin Staphylococcus and Enterococcus resistant were not found. The average procalcitonin (PCT) value of G^- bacteria infection was (11.02±20.282) ng/ml, while in G⁺ infection it was (1.81±4.911) ng/ml, the difference was statistically significant (P<0.05). The mean value of C-reactive protein (CRP) in G^- infection was (76.33±69.946) mg/L, and that in G⁺ infection was (38.34±57.951) mg/L. The prognosis of active treatment was good, and only one case died of septic shock complicated with disseminated intravascular coagulation (DIC) and gastrointestinal bleeding caused by carbapenemase-resistant enzyme enterobacteriaceae. CONCLUSION G^- is the major bacteria in acute leukemia children with bloodstream infection, but the distribution of ALL and AML strains is different. G^- bacteria dominates in ALL, while G⁺ bacteria and G^- bacteria are equally distributed in AML. Non-agranulocytosis accompanied by bloodstream infections is dominant by G⁺ bacteria. The mean value of PCT and CRP are significantly higher in G^- bacteria infection than in G⁺ bacteria.
Acute Disease ; Anti-Bacterial Agents/therapeutic use* ; Bacteremia/microbiology* ; Bacteria ; Child ; Drug Resistance, Bacterial ; Humans ; Leukemia, Myeloid, Acute/drug therapy* ; Microbial Sensitivity Tests ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Procalcitonin ; Retrospective Studies ; Sepsis/drug therapy*

No abstract available.
Aged ; Ampicillin/therapeutic use ; Anti-Bacterial Agents/therapeutic use ; Antimetabolites, Antineoplastic/therapeutic use ; Asian Continental Ancestry Group ; Cytarabine/therapeutic use ; Drug Therapy, Combination ; Humans ; Idarubicin/therapeutic use ; Leukemia, Myeloid, Acute/complications/*diagnosis/drug therapy ; Male ; Moraxella/genetics/*isolation & purification ; Moraxellaceae Infections/*diagnosis/drug therapy/microbiology ; RNA, Ribosomal, 16S/chemistry/genetics ; Republic of Korea ; Respiratory Tract Infections/diagnosis/microbiology ; Sequence Analysis, RNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Sulbactam/therapeutic use

OBJECTIVETo evaluate the efficacy and safety of antifungal prophylaxis of itraconazole in patients with acute myeloid leukemia (AML) to probe the relationship of the antifungal effect and the adverse events with serum concentration.

METHODSFrom April 2009 to May 2011, a total of 310 courses from 112 patients referred to our institute were enrolled in this study; of them, 297 courses were eligible for analysis. Eligible cases were randomized into oral group and injection/oral group according to different chemotherapy of induction and consolidation. Blood samples were collected at different time points for measurements of serum itraconazole levels. The morbidity of IFI and the adverse events were analyzed.

RESULTSThe morbidities of IFI in injection/oral and oral groups were 10.1% and 20.9%, respectively (P=0.010). 7 and 9 cases in injection/oral and oral groups, respectively were withdrawn from the study because of adverse events, and the difference between these two groups was of no significance. Serum itraconazole levels of injection/oral and oral groups were 672(299-1097) μg/L and 534(210-936) μg/L, respectively (P<0.01).

CONCLUSIONAntifungal prophylaxis with itraconazole in AML patients was effective and safe. Prophylactic effect with injection/oral itraconazole was superior to oral itraconazole solution; moreover, prophylactic effect of itraconazole was highly correlated with its serum level.

Adolescent ; Adult ; Antibiotic Prophylaxis ; Antifungal Agents ; therapeutic use ; Female ; Humans ; Itraconazole ; blood ; therapeutic use ; Leukemia, Myeloid, Acute ; drug therapy ; microbiology ; Male ; Middle Aged ; Mycoses ; etiology ; prevention & control ; Young Adult

We present four cases of concomitant early (modified Ficat-Arlet stage I) avascular necrosis of the femoral head and acute bacterial arthritis of the hip joint by Gram-negative enteric bacilli. This was found in immunosuppressed oncologic patients whose clinical presentations and radiological findings were not entirely specific for joint sepsis. It is important to recognise the coexistence of these two pathologies, so as to avoid a delay in diagnosis and prevent significant morbidity and mortality.
Acute Disease ; Adenocarcinoma ; complications ; microbiology ; Adult ; Arthritis, Infectious ; complications ; diagnosis ; Bacillus ; isolation & purification ; Contrast Media ; Female ; Femur Head Necrosis ; complications ; diagnosis ; Gram-Negative Bacteria ; isolation & purification ; Hodgkin Disease ; complications ; microbiology ; Humans ; Leukemia, Myeloid, Acute ; complications ; microbiology ; Lung Neoplasms ; complications ; microbiology ; Male ; Middle Aged ; Multiple Myeloma ; complications ; microbiology ; Neoplasms ; complications ; microbiology ; Risk Factors ; Young Adult

Sphingobacterium spiritivorum has been rarely isolated from clinical specimens of immunocompromised patients, and there have been no case reports of S. spiritivorum infection in Korea to our knowledge. We report a case of S. spiritivorum bacteremia in a 68-yr-old woman, who was diagnosed with acute myeloid leukemia and subsequently received chemotherapy. One day after chemotherapy ended, her body temperature increased to 38.3degrees C. A gram-negative bacillus was isolated in aerobic blood cultures and identified as S. spiritivorum by an automated biochemical system. A 16S rRNA sequencing analysis confirmed that the isolate was S. spiritivorum. The patient received antibiotic therapy for 11 days but died of septic shock. This is the first reported case of human S. spiritivorum infection in Korea. Although human infection is rare, S. spiritivorum can be a fatal opportunistic pathogen in immunocompromised patients.
Aged ; Anti-Bacterial Agents/therapeutic use ; Bacteremia/*complications/drug therapy/*microbiology ; Bone Marrow Cells/pathology ; Fatal Outcome ; Female ; Humans ; Immunocompromised Host ; Leukemia, Myeloid, Acute/*complications ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Shock, Septic/etiology/microbiology ; Sphingobacterium/classification/genetics/isolation & purification/*physiology

Tsukamurella pulmonis is an aerobic actinomycete. We report a catheter-related bacteremia of T. pulmonis. A 39 yr-old male with ALL was hospitalized to receive bone marrow transplantation (BMT). Although the patient developed a high fever at the 7th hospital day (HD), it subsided with vancomycin treatment, and he received BMT at 9th HD. Fever resurged at 16th HD despite sustained treatment with vancomycin, meropenem, and amphotericin B, but subsided with removal of Hickman catheter (HC) at 19th HD. Three sets of blood cultures comprising one from the HC and two from venipunctures were taken at 7th, 16th, and 19th HD, and the distal tip of the HC was also cultured. The aerobic vials of all 3 HC-withdrawn blood cultures and one peripheral blood culture taken at 19HD and the HC tip culture grew long, straight, thin gram-positive rods that were positive on modified Kinyoun stain. This organism showed tiny, rough, grey colonies after 3-day incubation and grew to large flat colonies when incubation was extended. It was catalase-positive, urease-positive, and alkaline-slant/alkaline-deep on triple sugar iron agar, and hydrolyzed hypoxanthine. The sequence of 1,296 base pairs of 16S rRNA of this organism showed a 100.0% homology with the published sequence of T. pulmonis DSM 44142T. To our knowledge, this is the first report of T. pulmonis bacteremia in Korea.
Actinomycetales/classification/genetics/isolation & purification ; Actinomycetales Infections/diagnosis/*microbiology/therapy ; Adult ; Bacteremia/*diagnosis/microbiology/therapy ; Bone Marrow Transplantation ; Catheter-Related Infections/*microbiology ; Humans ; Leukemia, Myeloid, Acute/therapy ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics

Gastrointestinal mucormycosis is an uncommon opportunistic fungal infection often presents in immunocompromised patients. Direct invasion of the intestinal walls by spores from ingested food is the main pathogenetic mechanism of this disease, which usually takes place in stomach and colon. Early diagnosis is critical, especially in vascular invasive types, due to its high mortality rate close to 100%. In the past when appropriate diagnostic tools were not available, mucormycosis were frequently found with autopsy. The advance in current endoscopic technology has increased diagnostic rate and made successful management available with appropriate treatments such as debridement of contaminated tissues. In this case report, we discussed a case of ileal mucormycosis diagnosed by colonoscopy and treated with anti-fungal agent successfully.
Amphotericin B/therapeutic use ; Antifungal Agents/therapeutic use ; Colonoscopy ; Humans ; Ileal Diseases/*diagnosis/microbiology/therapy ; Ileum/pathology ; Immunocompromised Host ; Leukemia, Myeloid, Acute/*complications/drug therapy ; Male ; Mucormycosis/*diagnosis/etiology/therapy ; Tomography, X-Ray Computed ; Young Adult

INTRODUCTIONStenotrophomonas maltophilia is an aerobic gram-negative bacillus that is a frequent coloniser of fluids used in the hospital setting. It causes infection in immunosuppressed hosts, especially those who are neutropaenic, on chemotherapy and broad spectrum antibiotics. Skin and soft tissue manifestations of Stenotrophomonas maltophilia infection are becoming an increasingly recognised entity; the clinical spectrum ranges from mucocutaneous, skin to soft tissue infections.

MATERIALS AND METHODSWe present a case of an 8-year-old girl with acute myeloid leukaemia who developed metastatic skin lesions secondary to Stenotrophomonas maltophilia bacteraemia. The authors reviewed a total of 24 reported cases of mucocutaneous, skin and soft tissue infections by Stenotrophomonas maltophilia. The presentations include metastatic cellulitis, primary cellulitis and infected mucocutaneous ulcers.

RESULTSThis is the first locally reported case of metastatic nodular skin lesions caused by Stenotrophomonas maltophilia bacteraemia. This is also the first reported paediatric case of embolic skin lesions caused by Stenotrophomonas maltophilia. Of the 6 cases of Stenotrophomonas maltophilia bacteraemia seen in the paediatric oncology patients from year 2000 to 2004 at our hospital, only 1 case developed metastatic skin lesions.

CONCLUSIONStenotrophomonas maltophilia skin infection should be included into the list of differential diagnoses for metastatic skin lesions in neutropaenic patients, especially with an underlying haematologic malignancy who has received recent chemotherapy and broad spectrum antibiotics. Haematologic malignancy, transplantation, neutropaenic, immunosuppressive therapy and a high severity of illness score were important prognostic factors.

Acute Disease ; Anti-Infective Agents ; therapeutic use ; Bacteremia ; epidemiology ; microbiology ; Cellulitis ; epidemiology ; microbiology ; Child ; Comorbidity ; Female ; Gram-Negative Bacterial Infections ; complications ; Humans ; Leukemia, Myeloid ; epidemiology ; Neutropenia ; epidemiology ; Prognosis ; Skin Diseases, Bacterial ; epidemiology ; Stenotrophomonas maltophilia ; Trimethoprim, Sulfamethoxazole Drug Combination ; therapeutic use

Scopulariopsis brevicaulis is a soil fungus normally associated with onychomycosis. It causes subcutaneous infection in immunocompromised patients and is rarely isolated from blood. A case of systemic Scopulariopsis brevicaulis infection was reported in a patient with acute myeloid leukemia. The patient developed persistent fever that did not respond to wide spectrum antibiotics and amphotericin B. Scopulariopsis brevicaulis was the only pathogen isolated from blood cultures. The fever subsided with itraconazole and there was no recurrence of fungal infection with prolonged maintenance of oral itraconazole.
Acute Disease ; Antifungal Agents/*therapeutic use ; Immunocompromised Host ; Itraconazole/*therapeutic use ; Leukemia, Myeloid/*complications ; Mycoses/*drug therapy ; Mycoses/*microbiology ; Opportunistic Infections/*drug therapy ; Opportunistic Infections/*microbiology