Intra-Abdominal Hypertension Contributes to the Development of Ventilator-Associated Pneumonia from Intestinal Bacteria.

Introduction: Ventilator-associated pneumonia (VAP) is an ICU (intensive care unit)-acquired pulmonary parenchymal infection that is complicated by mechanical ventilation and is associated with high morbidity and mortality. Klebsiella pneumoniae (KPN) is known to asymptomatically colonize the gastrointestinal tract and may increase the incidence of corresponding VAP. Our study aims were to investigate the exact origin of the carbapenem-resistant Klebsiella pneumoniae (CRKP) causing VAP in our patient. Methods: Various environmental samples, including the patient's anal swab, were collected in order to find the source of the bacteria. Minimum inhibitory concentrations (MICs) for antimicrobial agents were determined according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI); resistant genes were detected by using PCR and sequencing; clone relationships were analyzed by using multilocus-sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). The IAP values were obtained via urinary catheter. Results: One CRKP strain was detected in the patient's anal swab; this strain was confirmed with the same gene type as the strain isolated from the sputum. We found that the patient's intra-abdominal pressure (IAP) was 29.41, 27.06, 24.12, and 22.66 mmHg; the IAP was either equal to or above 12 mmHg, on the operation day and the following three days. Intra-abdominal hypertension (IAH) occurred during the patient's hospitalization and was considered to be caused by the surgical procedure. Meanwhile, we found that there was a correlation between IAH and the detection of CRKP in the sputum. The findings suggested that his VAP was caused by intestinal colonial KPN, and not from the environment. Discussion: Our research illustrated that the ST11 KPC-2-producing strain colonized the intestinal tract and caused the development of VAP when the IAP was elevated. Routine screening for the intestinal carriage of CRKP, among patients in ICUs, can limit and prevent current and future outbreaks.

Characterization of the Lytic Phage Flora With a Broad Host Range Against Multidrug-Resistant Escherichia coli and Evaluation of Its Efficacy Against E. coli Biofilm Formation.

Escherichia coli is a gram-negative bacterium that is distributed widely throughout the world; it is mainly found in contaminated food, the poultry industry, and animal feces. The emergence of antibiotic-resistant E. coli poses a threat to human and animal health, which has led to renewed interest in phage-based therapy. E. coli biofilm control and prevention are of great importance. In this study, the isolated phages Flora and KM18 were found to belong to the family Myoviridae; the optimal preservation buffer was pH = 6~7, and the phage genome sizes were 168,909 (Flora) and 168,903 (KM18) bp. Phage Flora had a broader lytic spectrum than KM18. Phage Flora had a better antibiofilm effect than kanamycin sulfate in high-concentration E. coli cultures. A combination of the phage Flora and kanamycin sulfate showed better antibiofilm effects than Flora or kanamycin sulfate alone in low-concentration E. coli cultures. These characteristics can serve as a guideline for the selection of effective candidates for phage therapy, in this case antibiotic-resistant E. coli control in the poultry industry.

Isolation and Characterization of a Lytic Staphylococcus aureus Phage WV against Staphylococcus aureus Biofilm.

BACKGROUND: Staphylococcus aureus is a Gram-positive, pathogenic bacterium that causes a wide range of symptoms in humans and can form biofilm, which is a multicellular community of microorganisms that attaches to nonbiological and biological surfaces. METHODS: Here, we aimed to isolate and characterize an S. aureus phage and examine the bactericidal activity alone and in conjunction with streptomycin treatment. RESULTS: We isolated a virulent phage, WV, from a slaughterhouse in Jiangsu, China. This strain belonged to the family Myoviridae and presented a genome size of 141,342 bp. The optimal pH of the preservation buffer was 6-7, optimal growth temperature was 37°C, and optimal multiplicity of infection was 0.01. Phage WV can sterilize most clinical strains of S. aureus that had been isolated from clinical patients in the First People's Hospital of the Yunnan Province. Against low-concentration S. aureus culture, streptomycin demonstrated a greater antibiofilm effect than that of phage WV. By contrast, in high-concentration S. aureus culture, phage WV demonstrated greater antibiofilm effect than that of streptomycin. The use of phage WV and streptomycin together had a substantially greater overall antibiofilm effect than that achieved using either component alone. CONCLUSION: This study provides strong evidence for the effectiveness of phage application for the reduction of S. aureus biofilm growth and suggests that phages can be considered as a viable alternative to antibiotics in clinical settings.

Expression of Leukocytic Syncytin-1 in B-Cell Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia Patients.

BACKGROUND: Syncytin-1 is improperly expressed in several cancers. However, its expression profile across leukocytes in leukemia patients has not yet been analyzed. METHODS: A total of 50 AML cases and 14 B-cell ALL patients were consecutively recruited. Bone marrow samples were subjected to flow cytometry. Statistical analysis was applied to compare syncytin-1 expression between B-cell ALL and AML across granulocytes, leukemia cells, and T-lymphocytes (including CD3+, CD4+, and CD8+ subsets thereof) and to correlate syncytin-1 expression to leukemia cells and lymphocytes with the T-cell subset percentages. RESULTS: The syncytin-1-expressing leukemia cell% in AML patients was significantly higher than that in B-cell ALL patients (p < 0.05). The CD8+ T-cell% in AML patients was significantly higher than that in B-cell ALL patients (p < 0.05). The syncytin-1 expression rate on leukemia cells was positively correlated with the CD8+ T-cell percentage (r = 0.289, p < 0.05), while the syncytin-1 expression rate on lymphocytes was negatively correlated with the CD3+, CD4+, and CD8+ T-cell percentages (r = -0.273, -0.450, and -0.307, respectively; p < 0.05). CONCLUSIONS: The percentage of syncytin-1-expressing leukemia cells in AML - due to its positive correlation with the CD8+ suppressor T-cell percentage - shows potential as an indicator of poorer long-term immunity in AML patients.

[Detection and analysis of immune molecules in leukemia cell surfaces of acute promyelocytic leukemia].

Objective To investigate the immunophenotypic characteristics of acute promyelocytic leukemia (APL) and its clinical significance. Methods Immunophenotyping was performed by four-color flow cytometry with CD45/SSC-lin gating for neoplastic cells and was divided into five levels according to the intensity of antigen expression. Results The expression intensity and percentage of typical APL phenotypes were: myeloperoxidase (MPO) and CD33 were consistently expressed (100%); CD38 (82.35%), CD13 (64.71%), CD64 (50%), CD123 (47.06%) and CD117 (44.12%) were partially expressed. HLA-DR (97.06%) and CD34 (99.02%) were negative. Post-chemotherapy remission rate in the Lym+APL patients was significantly lower than that in the Lym-APL patients. Conclusion The typical phenotypic characteristics in APL immunophenotyping were high SSC, CD33+ (grade I), CD38+ (grade I), MPO+ (grade I), CD13+ (grade III), CD64+ (grade I/III), CD117+ (grade II/III/IV), CD123+ (grade III/IV), CD11b-, HLA-DR-, CD34-. Understanding of the immunophenotypic features of APL contributes to rapid diagnosis of APL and the guidance of minimal residual disease (MRD) detection.

Upregulation of Leukocytic Syncytin-1 in Acute Myeloid Leukemia Patients.

BACKGROUND Syncytin-1, a cell membrane-localizing fusogen, is abnormally expressed in several cancers, including endometrial cancer, breast cancer, and leukemia. Although abnormal syncytin-1 expression has been detected in two-thirds of leukemia blood samples, its expression profile in acute leukemia patients has not yet been analyzed. MATERIAL AND METHODS Bone marrow samples from 50 acute myelogenous leukemia (AML) cases and 14 B-cell acute lymphocytic leukemia (B-cell ALL) patients were subjected to flow cytometry to assess leukocyte type distributions and leukocytic syncytin-1 surface expression. RT-PCR was applied to assess leukocytic syncytin-1 mRNA expression. Statistical analysis was applied to compare syncytin-1 expression between AML and B-cell ALL patients across blasts, granulocytes, lymphocytes, and monocytes as well as to determine clinical factors statistically associated with changes in syncytin-1 expression. RESULTS The leukocyte type distributions of the AML and B-cell ALL cohorts highly overlapped, with an observable difference in blast distribution between the 2 cohorts. The AML cohort displayed significantly greater syncytin-1 surface and mRNA expression (p<0.05). Syncytin-1 surface and mRNA expression was significantly increased across all 4 leukocyte types (p<0.05). The percentage of syncytin-1-expressing blasts was significantly greater in AML patients (p<0.05), with blasts showing the largest fold-change in syncytin-1 expression (p<0.05). M5, M5a, and M5b AML patients displayed significantly higher syncytin-1 surface expression relative to all other AML French-American-British (FAB) classifications (p<0.05). CONCLUSIONS These findings suggest leukocytic syncytin-1 expression may play a role in the development and/or maintenance of the AML phenotype and the acute monocytic leukemia phenotype in particular.