In Vitro Activities of Antibiotic Combinations Against Clinical Isolates of Pseudomonas Aeruginosa

Combination therapy has been recommended to treat Pseudomonas aeruginosa infections worldwide. The purpose of the present study was to determine the in vitro activities of piperacillin, cefepime, aztreonam, amikacin, and ciprofloxacin alone and in combination against 100 clinical isolates of P. aeruginosa from one medical center in southern Taiwan. The combination susceptibility assay was performed using the checkerboard technique. The percentage of resistance of P. aeruginosa to single agents in our study was relatively high for the Asia-Pacific area, except to aztreonam. Piperacillin plus amikacin exhibited the highest potential for synergy (59/100) in this study. Moreover, a high percentage of synergism was also noted with amikacin combined with cefepime (7/100) or aztreonam (16/100). The combination of two beta-lactams, such as cefepime with piperacillin, and aztreonam with cefepime or piperacillin, showed synergistic effects against some P. aeruginosa isolates. Although ciprofloxacin is a good anti-pseudomonal agent, a very low potential for synergy with other antibiotics was demonstrated in this study. No antagonism was exhibited by any combination in our study. Among piperacillin-resistant strains, there was synergy with a beta-lactam plus amikacin, including the combination of piperacillin and amikacin. However, the combination of two beta-lactams, such as piperacillin and cefepime or aztreonam, did not have any synergistic activity against these strains. In summary, the combinations of amikacin with the tested beta-lactams (piperacillin, aztreonam, cefepime) had a greater synergistic effect against P. aeruginosa, even piperacillin-resistant strains, than other combinations. Understanding the synergistic effect on clinical strains may help clinicians choose better empirical therapy in an area with high prevalence of multidrug-resistant P. aeruginosa

Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii on computer interface surfaces of hospital wards and association with clinical isolates

<p>Abstract</p> <p>Background</p> <p>Computer keyboards and mice are potential reservoirs of nosocomial pathogens, but routine disinfection for non-water-proof computer devices is a problem. With better hand hygiene compliance of health-care workers (HCWs), the impact of these potential sources of contamination on clinical infection needs to be clarified.</p> <p>Methods</p> <p>This study was conducted in a 1600-bed medical center of southern Taiwan with 47 wards and 282 computers. With education and monitoring program of hand hygiene for HCWs, the average compliance rate was 74% before our surveillance. We investigated the association of methicillin-resistant <it>Staphylococcus aureus </it>(MRSA), <it>Pseudomonas aeruginosa </it>and <it>Acinetobacter baumannii</it>, three leading hospital-acquired pathogens, from ward computer keyboards, mice and from clinical isolates in non-outbreak period by pulsed field gel electrophoresis and antibiogram.</p> <p>Results</p> <p>Our results revealed a 17.4% (49/282) contamination rate of these computer devices by <it>S. aureus</it>, <it>Acinetobacter </it>spp. or <it>Pseudomonas </it>spp. The contamination rates of MRSA and <it>A. baumannii </it>in the ward computers were 1.1% and 4.3%, respectively. No <it>P. aeruginosa </it>was isolated. All isolates from computers and clinical specimens at the same ward showed different pulsotypes. However, <it>A. baumannii </it>isolates on two ward computers had the same pulsotype.</p> <p>Conclusion</p> <p>With good hand hygiene compliance, we found relatively low contamination rates of MRSA, <it>P. aeruginosa </it>and <it>A. baumannii </it>on ward computer interface, and without further contribution to nosocomial infection. Our results suggested no necessity of routine culture surveillance in non-outbreak situation.</p

Association of Endostatin D104N with Leukemia

The bone marrow and/or peripheral blood from 126 patients with acute myeloid leukemia (AML), 57 with chronic myeloid leukemia (CML), 91 with acute lymphocytic leukemia (ALL), and 178 normal controls were analyzed using a polymerase chain reaction-restriction fragment length polymorphism (RFLP) assay to evaluate the association of the endostatin polymorphisms D104N (nucleotide 4349G→A) with leukemia. In the 178 normal Taiwanese, the allele frequency of 4349G was 98% (348/356) and that of 4349A was 2% (8/356). The frequencies of homozygous 4349G (104D/D) and heterozygous 4349G/A (104D/N) were 95. 5% (170/178) and 4.5% (8/178), respectively. However, no individuals were homozygous 4349A (104N/N). Among the leukemia patients, 124/126 with AML (98.4%), 55/57 with CML (94.9%), and 89/91 with ALL (97.9%) were homozygous 4349G. In addition, 2/126 with AML (1.6%), 2/57 with CML (5.1%), and 2/91 with ALL (2.1%) were heterozygous 4349G/A. No patients were homozygous 4349A. Similar frequencies of endostatin polymorphisms were observed in leukemic patients and normal controls. This suggests that the endostatin polymorphism is not associated with the risk of leukemia

Dengue Virus-Associated Hemophagocytic Syndrome and Dyserythropoiesis: A Case Report

A 33-year-old man had dengue hemorrhagic fever with initial presentation of fever, leukocytosis, and thrombocytopenia. The cause of the subsequent rapid decline in red cell counts without evidence of intravascular hemolysis or massive bleeding was confirmed as hemophagocytosis and dyserythropoiesis by bone marrow study. The patient recovered with supportive care and the bone marrow pattern was normal on repeated bone marrow study. To our knowledge, this is the first reported case of dengue virus-associated hemophagocytosis and dyserythropoiesis in Taiwan. Clinicians should consider that the occurrence of hemophagocytosis and dyserythropoiesis could be due to dengue virus infection. That this dengue virus infection was confirmed by a positive serology result at the convalescent stage but not at the acute symptomatic stage underlines the need for a second dengue serology study, as dengue infection can be missed due to an initial negative serology result

Risk Factors and Molecular Analysis of Community Methicillin-Resistant Staphylococcus aureus Carriage

A total of 1,838 subjects from the community and 393 subjects from health care-related facilities in Taiwan were evaluated for the prevalence of nasal Staphylococcus aureus colonization and to identify risk factors associated with S. aureus and methicillin-resistant S. aureus (MRSA) colonization. Among the community subjects, 3.5% had nasal MRSA colonization. Subjects from health care-related facilities had a lower S. aureus colonization rate (19.1%) than community subjects (25.2%) but had a significantly higher rate of colonization with MRSA (7.63%). Age (P < 0.001) was a significant risk factor for S. aureus colonization, with subjects under age 20 years or between 71 and 80 years showing higher rates of colonization. Recent gastrointestinal disease (P = 0.011) and hospital admission (P = 0.026) were risk factors for nasal MRSA colonization. Comparison of hospital MRSA isolates with the colonization strains by staphylococcal cassette chromosome mec (SCCmec) gene typing and pulsed-field gel electrophoresis (PFGE) typing revealed that most MRSA strains carried in the community were SCCmec type IV and that most clinical hospital isolates were type III, while health care facility-related carriage isolates were mainly SCCmec type III and type IV. Two new variant SCCmec types were identified. Six clusters of PFGE patterns were distinguished: two mainly comprised health care facility-related MRSA strains, three mainly comprised community MRSA strains, and one comprised mixed community and health care facility-related MRSA strains. In conclusion, a high prevalence of MRSA colonization was observed among people with no relationship to the hospital setting. The high level of multiple-drug resistance among community MRSA strains in association with the previously reported excessive use of antibiotics in Taiwan highlights the importance of the problem of antibiotic selective pressure. Our results indicate that both the clonal spread of MRSA and the transmission of hospital isolates contribute to the high MRSA burden in the community

Pure Red Cell Aplasia After ABO Major-Mismatched Allogeneic Peripheral Blood Stem Cell Transplantation Successfully Treated with Plasma Exchange and Low-Dose Steroid: Two Case Reports

Pure red cell aplasia (PRCA) is a complication of ABO-incompatible allogeneic stem cell transplantation. The mechanism is not well known, although the isoagglutinin titer before transplantation or cyclosporine use is considered to be the cause. Patients with this complication require more blood transfusions than those without it. There is no standard treatment. We report two cases of PRCA after allogeneic peripheral blood stem cell transplantation that were successfully treated with plasma exchange and low-dose steroid

Comparisons Between Allogeneic Peripheral Blood Stem Cell Transplantation and Allogeneic Bone Marrow Transplantation in Adult Hematologic Disease: A Single Center Experience

This retrospective study compared the outcomes in 32 adult patients with hematologic diseases (acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, myelodysplastic syndrome, severe aplastic anemia) who received allogeneic bone marrow transplantation (BMT, n = 14; median age, 28 years) or allogeneic peripheral blood stem cell transplantation (PBSCT, n = 18; median age, 29 years) from human leukocyte antigen-identical sibling donors. Median follow-up was 58 months in BMT recipients and 18 months in PBSCT recipients. Neutrophil (median, Day 8 vs Day 13, p < 0.001) and platelet engraftment (median, Day 9 vs Day 17, p < 0.001) was faster in the PBSCT group than in the BMT group. Patients receiving PBSCT required less platelet transfusion than those receiving BMT (median, 54 units vs 144 units, p < 0.001), but there was no significant difference in red cell transfusion. At 100 days, there was no difference in the incidence of acute graft-versus-host disease (GVHD) (42.9% vs 33.3%, p = 0.72) or grade II-IV acute GVHD (14.3% vs 5.6%, p = 0.57), and there was no difference in the cumulative incidence of chronic GVHD (20% vs 33.3%, p = 0.67). No chronic GVHD was noted in any relapsed patients (BMT, 5; PBSCT, 3), and no patients with chronic GVHD during follow-up had a relapse. Relapse was the most frequent cause of death in both groups (BMT, 5/9, 55.6%; PBSCT, 3/4, 75%; p = 0.25); all relapses occurred within 1 year after transplantation. Overall survival was significantly better in the PBSCT group (35.7% vs 77.8%, p = 0.029), but this difference was lost if only hematologic malignancies were analyzed (30.8% vs 63.6%, p = 0.20). Our results are similar to those reported previously, with faster neutrophil and platelet engraftment and less severe acute GVHD and extensive chronic GVHD with PBSCT. Allogeneic PBSCT is a feasible and beneficial alternative to allogeneic BMT in adult hematologic disease