Potentiation of Antitumor Effects of Cisplatin by Tumor Necrosis Factor-β

Recombinant tumor necrosis factor- potentiated the inhibitory effect of cisplatin on intramuscularly transplanted GA-1 tumor and liver metastasis in mice. The antitumor effect was related to cytotoxic and cytostatic activities of the test preparations rather than to initiation of apoptosis.     

Potentiation of murine innate immunity by α-galacturonosyl-type glycosphingolipids isolated from Sphingomonas yanoikuyae and S. terrae

Glycosphingolipids (GSLs) are components of the outer membrane of Sphingomonas species, commonly classified into two types, α-glucuronosyl ceramide (α-GlcACer) and α-galacturonosyl ceramide (α-GalACer), respectively. GSL-7 from S. yanoikuyae and GSL-13 from S. terrae, with α-GalACer-type structure, possess dihydrosphingosine but with a different ratio of C21cyclopropane to C20:1, while other parts remain similar. We therefore examined if this difference in the ratio of C21cyclopropane to C20:1 in the two ceramides may influence activation of, not only invariant natural killer T (iNKT) cells, but also other cells involved in innate immunity. GSL-7 with a large proportion of C21cyclopropane induced stronger activation of iNKT cells, natural killer cells, dendritic cells, and macrophages than GSL-13 with a large proportion of C20:1. The results show that a higher ratio of C21cyclopropane to C20:1 in the dihydrosphingosine molecule allows a more optimal activation of iNKT cells and other cell types.     

Detection of AmpC β-lactamases in Escherichia coli,Klebsiella spp., Salmonella spp. and Proteus mirabilis in a regional clinical microbiology laboratory

There are currently no standardized diagnostic tests available for the reliable detection of AmpC β-lactamases in Klebsiella spp., Escherichia coli, Proteus mirabilis and Salmonella spp. A study was designed to evaluate a confirmation disk test using cefotetan (CTT) and cefoxitin (FOX) with phenylboronic acid (PBA). It also investigated the most suitable screening concentrations of FOX, ceftriaxone (CRO) and ceftazidime (CAZ) for the detection of AmpC β-lactamases. A total of 126 control (consisting of 11 laboratory and 115 well-characterized clinical strains) and 29 840 non-repeat clinical isolates were included. FOX with PBA used in a confirmation test and CRO and CAZ as screening agents were found to be unreliable. FOX at ≥ 32 mg/L was the best screening agent and CTT with PBA was the best confirmation test. Of the clinical isolates 635 (2%) were found to be resistant to cefoxitin (MIC ≥ 32 ug/mL) and 332 (52%) were AmpC positive. E. coli was the most common organism with AmpC β-lactamases and was mostly present in urines from community patients. It is recommended that laboratories use FOX at 32 mg/L as a screening agent and perform a disk test with CTT and PBA to confirm the presence of an AmpC cephalosporinase in isolates of Klebsiella spp., E. coli, Salmonella spp. and P. mirabilis. This approach is convenient, practical and easy to incorporate into the workflow of a clinical laboratory. False-positive AmpC detection may occur with KPC-producing bacteria when inhibitor-based methods are used.     

Studies of the Mechanism of Development of “Deprivation” Potentiation of Population Responses of Neurons in Field CA1 of Living Hippocampal Slices

Experiments on rat hippocampal slices were performed with testing of the synaptic connections of Schaffer collaterals and neurons in field CA1 to study the effects of interrupting low-frequency test stimulation (0.05 Hz) on the amplitude of population spikes. These studies demonstrated a correlation between the duration of pauses in stimulation (form 10 to 120 min) and increases in the amplitude of spikes (on average by 30–100% of baseline response magnitude). This deprivation potentiation was additive and could persist for long periods of time (testing was up to 1 h). Preliminary induction of long-term post-tetanic potentiation, which prevented the subsequent development of the late, but not the short-term phase, for 1–3 h, led to suppression of the development of deprivation potentiation after a 60-min pause in stimulation. Similar results were obtained in experiments using 20 M polymyxin B, which blocks protein kinase C and the PKC-dependent phase of long-term post-tetanic potentiation; this is evidence supporting the previously advanced hypothesis that the development of deprivation potentiation and the late, PKC-dependent phase of long-term post-tetanic potentiation share common mechanisms, associated with people phosphorylation.     

Extended-spectrum β-lactamase producing Klebsiella spp. in chicken meat and humans: a comparison of typing methods

Recently, chicken meat was identified as a plausible source of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli in humans. We investigated the relatedness of ESBL-producing Klebsiella spp. in chicken meat and humans. Furthermore, we tested the performance of SpectraCell RA^® (River Diagnostics), a new typing method based on Raman spectroscopy, in comparison with multilocus sequence typing (MLST) for Klebsiella pneumoniae. Twenty-seven phenotypically and genotypically confirmed ESBL-producing Klebsiella spp. isolates were typed with MLST and SpectraCell RA. The isolates derived from chicken meat, human rectal swabs and clinical blood cultures. In the 22 ESBL-producing K. pneumoniae isolates, CTX-M15 was the predominant genotype, found in five isolates of human origin and in one chicken meat isolate. With MLST, 16 different STs were found, including five new STs. Comparing the results of SpectraCell RA with MLST, we found a sensitivity of 70.0% and a specificity of 81.8% for the new SpectraCell RA typing method. Therefore, we conclude that SpectraCell RA is not a suitable typing method when evaluating relationships of ESBL-producing Klebsiella spp. at the population level. Although no clustering was found with isolates of chicken meat and human origin containing the same ESBL genes, MLST showed no clustering into distinctive clones of isolates from chicken meat and human origin. More studies are needed to elucidate the role of chicken meat in the rise of ESBL-producing Klebsiella spp. in humans.     

Detection of extended-spectrum β-lactamase in Enterobacter spp.--evaluation of six phenotypic tests

Extended-spectrum β-lactamases (ESBL) are plasmid-mediated enzymes that hydrolyze cephalosporins and monobactams. The lack of a standard method to detect ESBL in Enterobacter spp. has led to underestimating its frequency. The aim of this study was to evaluate ESBL detection in Enterobacter spp. By the double-disk synergy test (DDST) and combined disk test (CDT) assay using cefepime, cefotaxime, and ceftazime as substrates for ESBL, plus AmpC inhibitors in different associations. A total of 83 Enterobacter spp. ESBL and 31 non-ESBL Enterobacter spp. were tested, and a cutoff point ≥3?mm was defined using a receiver operating characteristic (ROC) curve for combined disc methods. All tests showed 100% specificity. The sensitivity was 89.2% for DDST and CDT without AmpC inibitor, 90.4% in the combined disc test in Mueller-Hinton agar containing phenylboronic acid (CDT-PBAA), and 94% in the combined disc test in Mueller-Hinton agar containing cloxacillin (CDT-CLXA). Cefepime was the best substrate, mainly when AmpC inhibitors were not used. However, superior results were achieved when all cephalosporins were evaluated together. In conclusion, to improve ESBL detection in Enterobacter spp., some modifications in phenotypic tests are needed, such as to reduce the distance between the discs to 20?mm in DDST, to use a cutoff point for ≥3?mm on the CDT, and to include a cefepime disk or an inhibitor of AmpC in all tests.     

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in 1–2-month-old highland yaks in Qinghai Province,China

Parasitology Research - Cryptosporidium and Giardia are ubiquitous parasites that infect humans and animals. Few reports are available on the prevalence of these two protozoan parasites in yaks...     

Field evaluations of the efficacy and safety of Emodepside plus toltrazuril (Procox® oral suspension for dogs) against naturally acquired nematode and Isospora spp. infections in dogs

Three controlled, blinded and randomised multicentre field studies evaluated the efficacy and safety of a new formulation containing emodepside plus toltrazuril (Procox? suspension for dogs) against naturally acquired parasite infections in dogs. In two studies dogs positive for gastrointestinal nematodes and/or Isospora spp. were treated with emodepside/toltrazuril suspension (at least 0.45 mg emodepside plus 9 mg toltrazuril per kg body weight) or a reference product containing either milbemycin oxime plus praziquantel (Milbemax?) or sulfadimethoxine (Kokzidiol SD?) at recommended dose rates. The third study investigated efficacy against prepatent natural Isospora spp. infections in comparison to an untreated control group by enrolling Isospora- negative dogs that were at risk to develop a patent infection during the study.No suspected adverse drug reactions were observed in any of the 403 dogs enrolled in the three studies including 234 dogs treated with emodepside/toltrazuril suspension. In dogs treated with emodepside/toltrazuril suspension against nematode infection faecal egg counts were reduced by 100 % (reference product: 99.7 %). Similarly, in the dogs that had been treated against patent Isospora spp. infection, faecal oocyst counts were reduced by 100 % (reference product: 99.0 %). In both studies, statistical analysis demonstrated non-inferiority and even superiority to the reference products (p ≤ 0.009). Dogs treated with emodepside/toltrazuril suspension during suspected prepatent Isospora spp. infection had 98.7 % lower faecal oocyst counts after treatment compared to untreated dogs (p < 0.0001).The studies demonstrated that emodepside/toltrazuril suspension is safe and highly efficacious against nematodes and Isospora spp. under field conditions.     

Metallo-��-Lactamase-Producing Pseudomonas spp. in Korea: High Prevalence of Isolates with VIM-2 Type and Emergence of Isolates with IMP-1 Type

Purpose

Two Korean nationwide studies showed that metallo-β-lactamases (MBLs)-producing-Pseudomonas spp. are not rare. The aim of this study was to assess the trends of MBL-producing isolates among imipenem-resistant isolates of Pseudomonas spp.

Materials and Methods

Imipenem-resistant clinical isolates were collected from 23 hospitals and one commercial laboratory participating in the KONSAR program in 2005. Polymerase chain reaction (PCR) was used to detect MBL genes.

Results

Alleles of MBL genes were detected in 10.8% of 415 Pseudomonas aeruginosa and 66.7% of 12 P. putida isolates from 18 of 24 hospitals/laboratory. Among the 14 IMP-1-like and 39 VIM-2-like MBLs, emergence of IMP-6 was detected for the first time.

Conclusion

Prevalence of MBL-producing P. aeruginosa has not significantly increased, but IMP-6 emerged in P. aeruginosa.     

Potentiation of antitumor effect of NKT cell ligand, α-galactosylceramide by combination with IL-12 on lung metastasis of malignant melanoma cells1

The combined therapeutic effect of natural killer T (NKT) cell ligand α-galactosylceramide (α-GalCer) and IL-12 against highly metastatic B16-BL6-HM melanoma cells was investigated. In comparison with a single administration of α-GalCer or IL-12, the combined treatment of tumor-bearing mice with α-GalCer plus IL-12 caused a super-induction of serum IFN-γ levels, though α-GalCer-induced IL-4 production was rather inhibited. In parallel with the augmented IFN-γ production, the natural killing activity against YAC-1 cells and syngeneic B16- BL6-HM melanoma was greatly augmented by the combined therapy. The major effector cells responsible for natural killing activity induced by α-GalCer plus IL- 12 were enriched in both NK1.1⁺TCRαβ⁺ NKT cells and NK1.1⁺TCRαβ⁻ NK cells. The preventing effect of α-GalCer or IL-12 alone against lung metastasis of B16-BL6-HM was also enhanced by the combination therapy. The antitumor activity of α-GalCer was totally abolished in NKT-deficient mice. However, IL- 12-induced antitumor activity was not eliminated in NKT-deficient mice though it was inhibited by anti-asialo GM1 Ab treatment. These findings suggested that α-GalCer synergistically act with IL-12 to activate both NKT cells and NK cells, which may play a critical role in the strong prevention of distant tumor metastasis at early stages of tumor-bearing. These data will provide a novel tool for the prevention of tumor metastasis using NKT-specific ligands α-GalCer and IL-12. This revised version was published online in July 2006 with corrections to the Cover Date.     

Discrimination of the ITS1 types of Fasciola spp. based on a PCR–RFLP method

Molecular characterization is important for discriminating Fasciola specimens having the deoxyribonucleic acid (DNA) sequences of Fasciola hepatica, Fasciola gigantica, and both Fasciola species, since three Fasciola forms coexist in Asian countries. We have developed a restriction fragment length polymorphism of amplified DNA (PCR–RFLP) of the nuclear ribosomal internal transcribed spacer 1 (ITS1) region in Fasciola species. The band patterns of the fragments digested with a restriction enzyme, Rsa I, were accurately distinguished among the three forms of Fasciola. Amplicons with the sequences of F. hepatica and F. gigantica were divided into fragments of about 360, 100, and 60 bp, and 360, 170, and 60 bp, respectively, and amplicons with the sequences of both Fasciola species yielded fragments of 360, 170, 100, and 60 bp. The results of PCR–RFLP completely coincided with those of sequence analysis, and thus PCR–RFLP is a useful technique for determining the ITS1 type in Fasciola species.     

Follow-up blood cultures in E. coli and Klebsiella spp. bacteremia—opportunities for diagnostic and antimicrobial stewardship

European Journal of Clinical Microbiology & Infectious Diseases - Uncomplicated Enterobacteriaceae bacteremia is usually transient and may not require follow-up blood cultures (FUBC). This is a...     

The molecular characteristics of cefepime-susceptible Escherichia coli and Klebsiella spp. isolates with a positive β-lactamase screening test result but negative confirmation

A negative extended-spectrum β-lactamase (ESBL) phenotypic confirmation test result obtained after a positive ESBL screening test result but which was cefepime-susceptible (NCPSCS) using the Clinical and Laboratory Standards Institute (CLSI) methods has been observed among isolates of Escherichia coli and Klebsiella spp. in the antimicrobial surveillance program in Shanghai, China. Among isolates collected from Huashan Hospital in 2005, NCPSCS strains were observed in 2.5% of 433 E. coli isolates and in 1.2% of 562 Klebsiella spp. isolates. We then selected 11 E. coli isolates and seven Klebsiella spp. NCPSCS isolates. Transmission electron microscopy (TEM), SHV, plasmid-borne AmpC, and CTX-M type ESBL genes were detected by the polymerase chain reaction (PCR) method. We found that all except two K. pneumoniae strains of NCPSCS isolates producing ESBL and AmpC harbored a plasmid-borne CMY-2 or DHA-1 type AmpC enzyme. The majority of NCPSCS E. coli and K. pneumoniae strains from Shanghai harbor plasmid-borne AmpC enzyme, and we recommend that, when NCPSCS strains are identified, further work such as the PCR detection of ESBL genes is necessary to determine whether they will produce ESBLs. The ESBL-positive strains should be reported as resistant to cefepime according to the CLSI guidelines.     

Molecular characterization of Cryptosporidium spp. in dairy calves from the state of São Paulo, Brazil

Cryptosporidiosis is a common protozoan disease observed in a wide range of vertebrate hosts, including ruminants. Cattle can be a potential reservoir of Cryptosporidium spp., leading to environmental contamination with oocysts of zoonotic species. The molecular characterization of Cryptosporidium spp. isolated from cattle from the state of S?o Paulo, Brazil, was accomplished using nested polymerase chain reaction for amplification of fragments of the 18S rRNA gene and the glycoprotein GP60 gene, following sequencing of amplified fragments. Positivity for Cryptosporidium was found in 10.7% (21/196) of the samples. Four species of Cryptosporidium were identified: C. andersoni, C. bovis, C. parvum subtype IIaA15G2R1, and C. ryanae. To the best of our knowledge, this is the first report of infection by C. ryanae and C. parvum IIaA15G2R1 in cattle from Brazil.     

Prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China

In order to assess the prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China, we conducted a polymerase chain reaction (PCR)-based surveillance of OXA-type β-lactamase gene clusters for a total of 2,880 Acinetobacter spp. isolates collected from 23 Chinese provinces. All isolates were tested for susceptibility to 12 antimicrobial agents and showed high rates of resistance to all these agents except minocycline. We also found that the vast majority of carbapenem-resistant Acinetobacter spp. were OXA-23-like-producing isolates, predominantly Acinetobacter baumannii isolates. Besides, bla _OXA-58-like and bla _OXA-24-like genes were detected in 32 and 11 isolates, respectively, involving many provinces throughout China. Furthermore, these two carbapenem-resistance determinants were located on transferable plasmids in most cases, indicating an emerging threat for both OXA-58-like- and OXA-24-like-producing Acinetobacter spp. isolates in China. Interestingly, a novel homologue of the bla _OXA-143 gene was identified in a susceptible Acinetobacter pittii isolate. Overall, these observations suggest that the bla _OXA-23-harboring A. baumannii isolates are the most frequent carbapenem-resistant Acinetobacter spp. in China, and the bla _OXA-24-like and bla _OXA-58-like genes have emerged as potential threats of hospital outbreaks of multidrug-resistant Acinetobacter spp.     

Reinzüchtung von Simonsiella spp.

Zusammenfassung Es wird Über die Reinzüchtung vonSimonsiella muelleri undSimonsiella filiformis aus dem Rachen von Meerschweinchen berichtet und eine kurze Beschreibung der Arten gegeben.Herrn Professor Dr. F. W.Brauss zum 50. Geburtstag gewidmet.     

Prognostic factors in 264 adults with invasive Scedosporium spp. and Lomentospora prolificans infection reported in the literature and FungiScope®

Invasive Scedosporium spp. and Lomentospora prolificans infections are an emerging threat in immunocompromised and occasionally in healthy hosts. Scedosporium spp. is intrinsically resistant to most, L. prolificans to all the antifungal drugs currently approved, raising concerns about appropriate treatment decisions. High mortality rates of up to 90% underline the need for comprehensive diagnostic workup and even more for new, effective antifungal drugs to improve patient outcome. For a comprehensive analysis, we identified cases of severe Scedosporium spp. and L. prolificans infections from the literature diagnosed in 2000 or later and the FungiScope^® registry. For 208 Scedosporium spp. infections solid organ transplantation (n?=?58, 27.9%) and for 56?L. prolificans infection underlying malignancy (n?=?28, 50.0%) were the most prevalent risk factors. L. prolificans infections frequently presented as fungemia (n?=?26, 46.4% versus n?=?12, 5.8% for Scedosporium spp.). Malignancy, fungemia, CNS and lung involvement predicted worse outcome for scedosporiosis and lomentosporiosis. Patients treated with voriconazole had a better overall outcome in both groups compared to treatment with amphotericin B formulations. This review discusses the epidemiology, prognostic factors, pathogen susceptibility to approved and investigational antifungals, and treatment strategies of severe infections caused by Scedosporium spp. and L. prolificans.