Authors:Hagen Frickmann, N. Chantratita, Y. Gauthier, H. Neubauer, and R. Hagen
Discrimination of Burkholderia (B.) pseudomallei and B. mallei from environmental B. thailandensis is challenging. We describe a discrimination method based on sequence comparison of the ribosomal protein S21 (rpsU) gene.The rpsU gene was sequenced in ten B. pseudomallei, six B. mallei, one B. thailandensis reference strains, six isolates of B. pseudomallei, and 37 of B. thailandensis. Further rpsU sequences of six B. pseudomallei, three B. mallei, and one B. thailandensis were identified via NCBI GenBank. Three to four variable base-positions were identified within a 120-base-pair fragment, allowing discrimination of the B. pseudomallei/mallei-cluster from B. thailandensis, whose sequences clustered identically. All B. mallei and three B. pseudomallei sequences were identical, while 17/22 B. pseudomallei strains differed in one nucleotide (78A>C). Sequences of the rpsU fragment of ‘out-stander’ reference strains of B. cepacia, B. gladioli, B. plantarii, and B. vietnamensis clustered differently.Sequence comparison of the described rpsU gene fragment can be used as a supplementary diagnostic procedure for the discrimination of B. mallei/pseudomallei from B. thailandensis as well as from other species of the genus Burkholderia, keeping in mind that it does not allow for a differentiation between B. mallei and B. pseudomallei.
In spite of the developments in microbiological methods, blood cultures remain the cornerstone for the diagnosis of bacteraemia. Classically, minimum of two bottles are collected on a routine basis: an aerobic bottle, allowing preferential growth of aerobic and facultative anaerobic microorganisms, and an anaerobic bottle, providing suitable environment for strict anaerobic bacteria. Recent reports have documented a decrease in anaerobic bacteraemias and have questioned the need for routine anaerobic blood cultures. Bacteraemia due to anaerobic organisms occurs in 0.5–12% of blood cultures worldwide; however, recent studies from Europe and the USA presented inconsistent data regarding the prevalence of anaerobic bacteraemias between 1993 and 2006.The aims of this retrospective survey were to determine the prevalence of bacteraemias due to anaerobic bacteria and evaluate the importance of anaerobic blood cultures in a university hospital in Szeged, Hungary. We examined the occurrence of bacteraemias due to anaerobic bacteria during a 5-year period, from January 2005 to 2009, in order to identify current trends of anaerobic bacteraemias in our university.
Authors:A. Autengruber, M. Gereke, G. Hansen, C. Hennig, and Dunja Bruder
Immunological characterization of immune cells that reside in specific anatomic compartments often requires their isolation from the respective tissue on the basis of enzymatic tissue disintegration. Applying enzymatic digestion of primary splenocytes, we evaluated the impact of collagenase and dispase, two enzymes that are commonly used for the liberation of immune cells from tissues, on the detectability of 48 immunologically relevant surface molecules that are frequently used for flow cytometric identification, isolation, and characterization of immune cell subsets. Whereas collagenase treatment had only minor effects on surface expression of most molecules tested, dispase treatment considerably affected antibody-mediated detectability of the majority of surface markers in subsequent FACS analyses. This effect was long lasting and, in case of high-dose dispase treatment, evident for the majority of surface molecules even after 24 h of in vitro culture. Of note, high-dose dispase treatment not only affected surface expression of certain molecules but also impaired antigen-specific proliferation of CD4+ and CD8+ T cells. Together, our data indicate that enzymatic tissue disintegration can have profound effects on the expression of a variety of cell-surface molecules with direct consequences for phenotypic analysis, FACS- and MACS-based target cell isolation, and immune cell function in cell culture experiments.
Authors:É. Nemes-Nikodém, E. Vörös, K. Pónyai, L. Párducz, S. Kárpáti, F. Rozgonyi, and Eszter Ostorházi
From January 1, 2009 through December 31, 2011, from 33,753 blood samples for syphilis screening, Treponema pallidum infections were confirmed in 241 pregnant women at the Department of Dermatology, Venerology, and Dermatooncology of Semmelweis University Budapest. In this period, four children born to inadequately or untreated women were confirmed to have connatal syphilis. The height of rapid plasma reagin (RPR) titer was measured to determine the stage of the infection and to examine the success of the antilues therapy. The diagnosis of maternal syphilis infection was confirmed with enzyme linked immunosorbent assay (ELISA), T. pallidum particle agglutination (TPPA), and IgG and IgM immunoblots. Maternal IgM immunoblot results identify mothers at risk of delivering babies with connatal syphilis better than the height of maternal RPR titer. The standard serological tests are less useful in newborns because of IgG transfer across the placenta. IgM test which depends on the infant’s response has more specificity in diagnosing connatal syphilis.
Monocytes are important cell types of the innate immune system. Recent scientific evidence suggests that monocytes not only play a crucial role in our innate immune system by defending the host from intruding microbial pathogens but they also contribute to the pathogenesis and progression of diseases such as liver fibrosis, atherosclerosis, multiple sclerosis, and tumor metastasis. In addition, monocytes and monocyte-derived macrophages play a crucial beneficial role in the liver fibrosis regression, muscle regeneration, and the clearance of the β-amyloid plaques in Alzheimer’s disease. Here, we summarize the origin, plasticity, and pathogenic potential of monocytes and monocyte-derived macrophages, as well as their positive role in the regression of some common diseases. Elucidating the comprehensive immunological role of monocytes will provide therapeutic advantages in either controlling disease progression or favoring the regression of the disease state.
Authors:Yoshiaki Kumamoto, T. Matsumoto, M. Fujisawa, and S. Arakawa
This prospective, multicenter clinical trial was conducted to compare the performance of the cobas® 4800 CT/NG, APTIMA Combo 2®, and ProbeTec™ ET CT/GC assays for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in Japan. From 1274 male and female patients, more than 1900 urine, endocervical and throat specimens were collected. Positive and negative concordance rates for CT and NG results obtained for urine and endocervical samples collected from the same patient were high in all three assays (range 96.0–99.6%). The accuracy of the cobas® 4800 CT/NG test did not differ significantly from that of the APTIMA Combo 2® and ProbeTec™ ET CT/GC assays. The accuracy of the assays did not change depending on the order of collection of endocervical specimens. Concordance rates for results obtained for throat swabs and mouthwashes in the ProbeTec™ ET CT/GC and cobas® 4800 CT/NG assays, respectively, were 98.8% for CT and 95.1% for NG. These data suggest that the cobas®4800 CT/NG test is a reliable and highly accurate diagnostic tool for the detection of CT and NG in urine, genital, and oral specimens. Owing to the high correlation of urine and endocervical swab results and the ease of acquisition, urine samples are suggested as the specimen of choice for screening of CT and NG.
Authors:Andrea Blaskó, Roberta Fajka-Boja, Gabriela Ion, and Éva Monostori
Galectin-1 (Gal-1), a mammalian lectin induces apoptosis of T lymphocytes. Contradictory data have resulted in confusing knowledge regarding mechanism of Gal-1 induced T-cell apoptosis. In this paper we aimed to resolve this controversy by comparing cell death induced by low (1.8 μM, lowGal-1) and high (18 μM, highGal-1) concentration of soluble Gal-1. We show that lowGal-1 and highGal-1 trigger phosphatidylserine exposure, generation of rafts and mitochondrial membrane depolarization. In contrast, lowGal-1 but not highGal-1 is dependent on the presence of p56lck and ZAP70 and activates caspase cascade. The results allow the conclusion that the cell-death mechanism strictly depends on the concentration of Gal-1.
Colonized vertebrates including humans and pigs are to date the main reservoirs of livestock-associated Methicillin-resistant Staphylococcus aureus (LA-MRSA). Currently, the mechanisms underlying colonization of pigs are not fully understood.
We investigated the influence of piglet pre-immune status on airborne MRSA colonization. Three groups of MRSA-negative piglets were primed and exposed to airborne LA-MRSA (104 colony forming units (cfu)/m3) in an aerosol chamber for 24 h. One group was treated intramuscularly with dexamethasone (1 mg/kg body weight) to imitate weaning stress. The second group was exposed to bacterial endotoxin containing MRSA aerosol. Both conditions play a role in the development of multifactorial diseases and may promote MRSA colonization success. The third group served as control.
The piglets' MRSA status was monitored for 21 days via swab samples. At necropsy, specific tissues and organs were analyzed. Blood was collected to examine specific immunological parameters.
The duration of MRSA colonization was not extended in both treated groups compared to the control group, indicating the two immune-status influencing factors do not promote MRSA colonization. Blood sample analysis confirmed a mild dexamethasone-induced immune suppression and typical endotoxin-related changes in peripheral blood. Of note, the low-dose dexamethasone treatment showed a trend of increased MRSA clearance.