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- Improving the Th1 cellular efficacy of the lead Yersinia pestis rF1-V subunit vaccine using SA-4-1BBL as a novel adjuvant. [JOURNAL ARTICLE]
- Vaccine 2014 Jul 18.
The lead candidate plague subunit vaccine is the recombinant fusion protein rF1-V adjuvanted with alum. While alum generates Th2 regulated robust humoral responses, immune protection against Yersinia pestis has been shown to also involve Th1 driven cellular responses. Therefore, the rF1-V-based subunit vaccine may benefit from an adjuvant system that generates a mixed Th1 and humoral immune response. We herein assessed the efficacy of a novel SA-4-1BBL costimulatory molecule as a Th1 adjuvant to improve cellular responses generated by the rF1-V vaccine. SA-4-1BBL as a single adjuvant had better efficacy than alum in generating CD4(+) and CD8(+) T cells producing TNFα and IFNγ, signature cytokines for Th1 responses. The combination of SA-4-1BBL with alum further increased this Th1 response as compared with the individual adjuvants. Analysis of the humoral response revealed that SA-4-1BBL as a single adjuvant did not generate a significant Ab response against rF1-V, and SA-4-1BBL in combination with alum did not improve Ab titers. However, the combined adjuvants significantly increased the ratio of Th1 regulated IgG2c in C57BL/6 mice to the Th2 regulated IgG1. Finally, a single vaccination with rF1-V adjuvanted with SA-4-1BBL+alum had better protective efficacy than vaccines containing individual adjuvants. Taken together, these results demonstrate that SA-4-1BBL improves the protective efficacy of the alum adjuvanted lead rF1-V subunit vaccine by generating a more balanced Th1 cellular and humoral immune response. As such, this adjuvant platform may prove efficacious not only for the rF1-V vaccine but also against other infections that require both cellular and humoral immune responses for protection.
- [Does the Hospital Cost of Care Differ for Inflammatory Bowel Disease Patients with or without Gastrointestinal Infections? - A Case-Control Study]. [English Abstract, Journal Article]
- Z Gastroenterol 2014 Jul; 52(7):643-8.
Objective:Gastrointestinal Infections have been implicated as possible causes of exacerbation of inflammatory bowel disease (IBD) or risk factors for severe flares in general. The introduction of the G-DRG reimbursement system has greatly increased the pressure to provide cost effective treatment in German hospitals. Few studies have compared the costs of treating IBD patients with or without gastrointestinal infections and none of them have specifically considered the German reimbursement situation.
Methods:We performed a single center case-control retrospective chart review from 2002 to 2011 of inpatients with IBD (Department of Internal Medicine IV, University Hospital Jena) with an exacerbation of their disease. The presence of gastrointestinal infections (Salmonella, Shigella, Campylobacter, Yersinia, adeno-, rota-, norovirus and Clostridium difficile) was assessed in all inpatients with Cohn's disease (CD) and ulcerative colitis (UC). IBD patients with gastrointestinal infections (n = 79) were matched for age to IBD patients who were negative for gastrointestinal pathogens (n = 158). Patient level costing (PLC) was used to express the total cost of hospital care for each patient; PLC comprised a weighted daily bed cost plus cost of all medical services provided (e. g., endoscopy, microbiology, pathology) calculated according to an activity-based costing approach. All costs were discounted to 2012 values.
Results:Gastrointestinal infections in IBD patients were not associated with an increase in mortality (0 %); however, they were associated with 2.3-fold higher total hospital charges (6499.10 € vs. 2817.00 €; p = 0.001) and increased length of stay in hospital (14.5 vs. 9.4 days; p < 0.0001). Despite increased reimbursement by DRG for IBD patients with gastrointestinal infections compared to patients without infections (3833.90 € vs. 2553.50 €; p = 0.005), hospital care in these patients was substantially underfunded (deficit - 2496.80 € vs. - 433.10 €) because of increased length of stay with personnel costs, especially in UC.
Conclusion:Inpatient hospital costs differ significantly for IBD patients with and without gastrointestinal infections, especially in ulcerative colitis, when care was provided in a single university hospital.
- Bacterial foodborne infections after hematopoietic cell transplantation. [JOURNAL ARTICLE]
- Biol Blood Marrow Transplant 2014 Jul 11.
Diarrhea, abdominal pain and fever are common among patients undergoing hematopoietic cell transplant (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence post-transplant within a single-center population of HCT recipients.All HCT recipients transplanted from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, WA were followed for one year post-transplant. Data were collected retrospectively using center databases, which include information from transplant, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli 0157:H7, Salmonella species, Shigella species, Vibrio species or Yersinia species were isolated in culture within one-year post-transplant. Non-foodborne infections with these agents and patients with preexisting bacterial foodborne infection (within 30 days of transplant) were excluded from analyses.A total of 12/4069 (0.3%) patients developed a bacterial foodborne infection within one year post-transplant. Patients with infections had a median age at transplant of 50.5 years (interquartile range [IQR]: 35-57), and the majority were adults ≥18 years of age (9/12 [75%]), male gender (8/12 [67%]) and post-allogeneic transplant (8/12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% CI: 0.5-1.7) and at a median of 50.5 days after transplant (IQR: 26-58.5). The most frequent pathogen detected was Campylobacter jejuni/coli (5/12 [42%]) followed by Yersinia (3/12 [25%]), while Salmonella (2/12 [17%]) and Listeria (2/12 [17%]) showed equal frequencies; no cases of Shigella, Vibrio, or E. coli 0157:H7 were detected. Most patients were diagnosed via stool (8/12 [67%]), fewer through blood (2/12 [17%]), one via both stool and blood simultaneously, and one through urine. Mortality due to bacterial foodborne infection was not observed during follow-up.Our large single-center study indicates that common bacterial foodborne infections were a rare complication following HCT, and the few cases that did occur resolved without complications. These data provide important baseline incidence for future studies evaluating dietary interventions for HCT patients.
- Yersinia ruckeri Biotypes 1 and 2 in France: presence and antibiotic susceptibility. [Journal Article]
- Dis Aquat Organ 2014 May 13; 109(2):117-26.
Yersinia ruckeri is the causative agent of yersiniosis, a disease reported in a number of fish species, especially rainbow trout. This study was undertaken to describe the phenotypes of Y. ruckeri on French rainbow trout farms. More than 100 isolates, collected during recent outbreaks on trout farms, were characterized by phenotypic tests, namely using biochemical tests of the API 20E system, serotyping, biotyping (tests for motility and lipase activity) and by describing the pattern of susceptibility to several antibiotics. The isolates showed a low phenotypic diversity with a prevalent serotype (O1) and API 20E profile 5 1(3)07 100. As in other European countries, Biotype 2 (BT2), which lacks both motility and secreted lipase activity, was found to be present in France. The emergence of 'French' BT2 was different than that observed for other European countries (Finland, Spain, Denmark and the UK). The antibiotic pattern was uniform for all isolates, regardless of the geographical area studied. The results indicate that no resistance has yet emerged, and the efficacy of the antibiotic generally used against yersiniosis in France, trimethoprim/sulfamethoxasol, is not compromised (minimum inhibitory concentrations [MIC] of between 0.016 and 0.128 µg ml-1). Enrofloxacin and doxycycline, not used as a first-line treatment in fish diseases, have reasonably good efficacies (with MICs ≤0.128 and 0.256, respectively).
- Bioserotypes and virulence markers of Y. enterocolitica strains isolated from roe deer (Capreolus capreolus) and red deer (Cervus elaphus). [Journal Article, Research Support, Non-U.S. Gov't]
- Pol J Vet Sci 2014; 17(2):315-9.
Free-living animals are an important environmental reservoir of pathogens dangerous for other animal species and humans. One of those is Yersinia (Y.) enterocolitica, the causative agent of yersiniosis--foodborne, enzootic disease, significant for public health. The purpose of the study was to identify bioserotypes and virulence markers of Y enterocolitica strains isolated from roe deer (Capreolus capreolus) and red deer (Cervus elaphus) obtained during the 2010/2011 hunting season in north-eastern Poland. From among 48 rectal swabs obtained from 24 roe deer, two strains of Y enterocolitica from one animal were isolated. Although both belonged to biotype 1A they were identified as different serotypes. The strain obtained from cold culture (PSB) belonged to serotype 0:5, while the strain isolated from warm culture (ITC) was regarded as nonidentified (NI), what may suggest mixed infection in that animal. The presence of ystB gene, coding for YstB enterotoxin, directly related to Y enterocolitica pathogenicity was detected in both strains using triplex PCR. The effect of the examination of 32 swabs obtained from 16 red deer was the isolation of two Y enterocolitica strains from two different animals. Both belonged to biotype 1A with NI serotype, but were originated from different types of culture. They gave positive results in case of products of a size corresponding to the ystB gene. No amplicons corresponding to ail and ystA genes were found. Roe deer and red deer may carry and shed Y. enterocolitica, what seems to be important in aspect of an environmental reservoir of this pathogen. The Y enterocolitica strains isolated from wild ruminants had the amplicons of the ystB gene, what suggest they can be potential source of Y enterocolitica infection for humans.
- [Microbiological diagnosis of infections caused by Campylobacter jejuni and Campylobacter coli in humans]. [English Abstract, Journal Article]
- Postepy Hig Med Dosw (Online) 2014; 68(0):48-56.
Campylobacter jejuni and Campylobacter coli are Gram-negative, microaerophilic bacteria which are worldwide in distribution, causing a zoonotic disease in humans called campylobacteriosis. These infections are mainly caused by eating contaminated food products, most often improperly prepared poultry meat. Campylobacteriosis usually takes the form of gastroenteritis, or inflammation of the intestines, and the characteristic symptoms are watery-mucous diarrhea often with the presence of blood in stool, nausea, vomiting, abdominal pain and fever.The epidemiological data suggest that in Europe, as well as in North America, bacteria of the genus Campylobacter, especially C. jejuni and C. coli, are the most commonly isolated pathogens in infections of the gastrointestinal tract in humans. Epidemiological data indicate that these organisms are a much more common cause of acute diarrhea, mostly in young children, than Salmonella and Yersinia. The lack of specific symptoms makes the diagnosis of campylobacteriosis necessary to carry out specialized microbiological diagnostics. Because so far these studies are performed in our country only in a few laboratories, the overwhelming number of cases of campylobacteriosis are not recorded in Polish epidemiological statistics. The purpose of this paper is to discuss issues related to the microbiological diagnosis of infections caused by C. jejuni and C. coli. It also describes the basic epidemiological and clinical data, as well as current treatment of campylobacteriosis.
- IQGAP1 Is Important for Activation of Caspase-1 in Macrophages and Is Targeted by Yersinia pestis Type III Effector YopM. [Journal Article]
- MBio 2014; 5(4)
YopM is a leucine-rich repeat (LRR)-containing effector in several Yersinia species, including Yersinia pestis and Y. pseudotuberculosis. Different Yersinia strains encode distinct YopM isoforms with variable numbers of LRRs but conserved C-terminal tails. A 15-LRR isoform in Y. pseudotuberculosis YPIII was recently shown to bind and inhibit caspase-1 via a YLTD motif in LRR 10, and attenuation of YopM(-) YPIII was reversed in mice lacking caspase-1, indicating that caspase-1 inhibition is a major virulence function of YopM(YPIII). To determine if other YopM proteins inhibit caspase-1, we utilized Y. pseudotuberculosis strains natively expressing a 21-LRR isoform lacking the YLTD motif (YopM(32777)) or ectopically expressing a Y. pestis 15-LRR version with a functional (YopM(KIM)) or inactivated (YopM(KIM) D271A) YLTD motif. Results of mouse and macrophage infections with these strains showed that YopM(32777), YopM(KIM), and YopM(KIM) D271A inhibit caspase-1 activation, indicating that the YLTD motif is dispensable for this activity. Analysis of YopM(KIM) deletion variants revealed that LRRs 6 to 15 and the C-terminal tail are required to inhibit caspase-1 activation. YopM(32777), YopM(KIM), and YopM(KIM) deletion variants were purified, and binding partners in macrophage lysates were identified. Caspase-1 bound to YopM(KIM) but not YopM(32777). Additionally, YopM(KIM) bound IQGAP1 and the use of Iqgap1(-/-) macrophages revealed that this scaffolding protein is important for caspase-1 activation upon infection with YopM(-) Y. pseudotuberculosis. Thus, while multiple YopM isoforms inhibit caspase-1 activation, their variable LRR domains bind different host proteins to perform this function and the LRRs of YopM(KIM) target IQGAP1, a novel regulator of caspase-1, in macrophages.Activation of caspase-1, mediated by macromolecular complexes termed inflammasomes, is important for innate immune defense against pathogens. Pathogens can, in turn, subvert caspase-1-dependent responses through the action of effector proteins. For example, the Yersinia effector YopM inhibits caspase-1 activation by arresting inflammasome formation. This caspase-1 inhibitory activity has been studied in a specific YopM isoform, and in this case, the protein was shown to act as a pseudosubstrate to bind and inhibit caspase-1. Different Yersinia strains encode distinct YopM isoforms, many of which lack the pseudosubstrate motif. We studied additional isoforms and found that these YopM proteins inhibit caspase-1 activation independently of a pseudosubstrate motif. We also identified IQGAP1 as a novel binding partner of the Yersinia pestis YopM(KIM) isoform and demonstrated that IQGAP1 is important for caspase-1 activation in macrophages infected with Yersinia. Thus, this study reveals new insights into inflammasome regulation during Yersinia infection.
- Epidemiology of Pathogenic Enterobacteria in Humans, Livestock, and Peridomestic Rodents in Rural Madagascar. [JOURNAL ARTICLE]
- PLoS One 2014; 9(7):e101456.
Among the families of enteric bacteria are globally important diarrheal agents. Despite their potential for zoonotic and environmental transmission, few studies have examined the epidemiology of these pathogens in rural systems characterized by extensive overlap among humans, domesticated and peridomestic animals. We investigated patterns of infection with Enterotoxigenic Escherichia coli, Shigella spp., Salmonella enterica, Vibrio cholerae, and Yersinia spp. (enterocolitica, and pseudotuberculosis) in Southeastern Madagascar where the potential for the aforementioned interactions is high. In this pilot project we conducted surveys to examine behaviors potentially associated with risk of infection and if infection with specific enterobacteria species was associated with diarrheal disease.PCR was conducted on DNA from human, livestock, and rodent fecal samples from three villages. Overall, human prevalence was highest (77%), followed by rodents (51%) and livestock (18%). Rodents were ∼2.8 times more likely than livestock to carry one of the bacteria. The incidence of individual species varied between villages, with the observation that, E. coli and Shigella spp. were consistently associated with co-infections. As an aggregate, there was a significant risk of infection linked to a water source in one village. Individually, different pathogens were associated with certain behaviors, including: those who had used medication, experienced diarrhea in the past four weeks, or do not use toilets.Different bacteria were associated with an elevated risk of infection for various human activities or characteristics. Certain bacteria may also predispose people to co-infections. These data suggest that a high potential for transmission among these groups, either directly or via contaminated water sources. As these bacteria were most prevalent in humans, it is possible that they are maintained in humans and that transmission to other species is infrequent. Further studies are needed to understand bacterial persistence, transmission dynamics, and associated consequences in this and similar systems.
- Nitropropenyl benzodioxole, an anti-infective agent with action as a protein tyrosine phosphatase inhibitor. [Journal Article]
- Open Med Chem J 2014.:1-16.
We report on the activities of a broad spectrum antimicrobial compound,nitropropenyl benzodioxole (NPBD) which are of relevance to its potential as an anti-infective drug. These investigations support the proposal that a major mechanism of NPBD is action as a tyrosine mimetic, competitively inhibiting bacterial and fungal protein tyrosine phosphatases (PTP). NPBD did not affect major anti-bacterial drug targets, namely, ATP production, cell wall or cell membrane integrity, or transcription and translation of RNA. NPBD inhibited bacterial YopH and human PTP1B and not human CD45 in enzyme assays. NPBD inhibited PTP-associated bacterial virulence factors, namely, endospore formation in Bacillus cereus, prodigiosin secretion in Serratia marcescens , motility in Proteus spp., and adherence and invasion of mammalian cells by Yersinia enterocolitica . NPBD acts intracellularly to inhibit the early development stages of the Chlamydia trachomatis infection cycle in mammalian cells known to involve sequestration of host cell PTPs. NPBD thus both kills pathogens and inhibits virulence factors relevant to early infection, making it a suitable candidate for development as an anti-infective agent, particularly for pathogens that enter through, or cause infections at, mucosal surfaces. Though much is yet to be understood about bacterial PTPs, they are proposed as suitable anti-infective targets and have been linked to agents similar to NPBD. The structural and functional diversity and heterogeneous distribution of PTPs across microbial species make them suitably selective targets for the development of both broadly active and pathogen-specific drugs.
- Simple, specific, sensitive and rapid loop-mediated method for detecting Yersinia enterocolitica. [Journal Article, Research Support, Non-U.S. Gov't]
- Southeast Asian J Trop Med Public Health 2014 May; 45(3):670-9.
Yersinia enterocolitica (YE) is a main pathogenic bacterium causing diarrhea and yersiniosis occurs in both developed and developing countries with high incidence. YE in contaminated food is able to survive for a long duration even under cold storage, thereby enhancing the risk of food infection. In this study, a new loop-mediated isothermal amplification (LAMP) method showing the characteristics of simplicity, rapidity, high specificity and sensitivity was established by targeting outL of pathogenic YE. Two inner-primers and outer-primers were designed and LAMP reaction was optimized for Mg2+, betaine, dNTPs and inner primers concentrations, reaction temperature and time. Sensitivity and specificity of the LAMP assay was evaluated using YE genomic DNA and those of 44 different bacteria strains, respectively. Validation of LAMP detection method was by employing meat samples spiked with varying CFU of YE. The optimized LAMP assay was specific, capable of detecting 97 fg of genomic DNA (equivalent to 37 genome copies) of YE (100-fold more sensitive than PCR) and 80 CFU/ml of YE-spiked meat samples based on ethidium bromide stained amplicon bands on agarose gel-electrophoresis and on GelRed fluorescence of the LAMP reaction solution, respectively. This rapid, sensitive and specific LAMP technique should enable application in field inspection of Y. enterocolitica in food.