Fine-Scale Phylogeographic Structure of Borrelia lusitaniae Revealed by Multilocus Sequence Typing

Borrelia lusitaniae is an Old World species of the Lyme borreliosis (LB) group of tick-borne spirochetes and prevails mainly in countries around the Mediterranean Basin. Lizards of the family Lacertidae have been identified as reservoir hosts of B. lusitaniae. These reptiles are highly structured geographically, indicating limited migration. In order to examine whether host geographic structure shapes the evolution and epidemiology of B. lusitaniae, we analyzed the phylogeographic population structure of this tick-borne bacterium using a recently developed multilocus sequence typing (MLST) scheme based on chromosomal housekeeping genes. A total of 2,099 questing nymphal and adult Ixodes ricinus ticks were collected in two climatically different regions of Portugal, being ~130 km apart. All ticks were screened for spirochetes by direct PCR. Attempts to isolate strains yielded 16 cultures of B. lusitaniae in total. Uncontaminated cultures as well as infected ticks were included in this study. The results using MLST show that the regional B. lusitaniae populations constitute genetically distinct populations. In contrast, no clear phylogeographic signals were detected in sequences of the commonly used molecular markers ospA and ospC. The pronounced population structure of B. lusitaniae over a short geographic distance as captured by MLST of the housekeeping genes suggests that the migration rates of B. lusitaniae are rather low, most likely because the distribution of mediterranean lizard populations is highly parapatric. The study underlines the importance of vertebrate hosts in the geographic spread of tick-borne microparasites.     

A comparison of 14 antibodies for the biochemical detection of the cystic fibrosis transmembrane conductance regulator protein

Interest in the biochemical detection of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein followed soon after cloning of the gene and prediction of the protein structure. Ever since, antibodies (Abs) have been produced and used to detect CFTR in both heterologously and endogenously expressing cells and tissues. Although designed to be sensitive and specific, these Abs produce, in most cases, unsatisfactory results when used for the biochemical detection of CFTR either by Western blot or by immunoprecipitation. The lack of Abs that can reliably detect the CFTR protein is a major constraint to studies of CF. We compared 14 different Abs for their ability to detect CFTR in both stably transfected and endogenously expressing cell lines.     

Utilization of Subcutaneous Methotrexate in Rheumatoid Arthritis Patients After Failure or Intolerance to Oral Methotrexate: A Multicenter Cohort Study

Introduction

Low-dose weekly methotrexate (MTX) is the mainstay in the therapy of rheumatoid arthritis (RA). It can be given via oral, intramuscular or subcutaneous (SC) route. This study sought to determine the real-world pattern of treatment with SC MTX in Portuguese adult patients with active RA.

Methods

Utilization of Metoject^® in Rheumatoid Arthritis (UMAR) was a non-interventional, cohort multicenter study with retrospective data collection. Eligible patients had active RA, at least 18 years of age, and started SC MTX treatment in 2009 or 2010 after failure or intolerance to oral MTX. Data were collected from patient’s clinical records. Both non-parametric and parametric survival methods were used to obtain a detailed understanding of SC MTX treatment duration.

Result

Fifty patients were included, of which only 9 discontinued SC MTX during the study follow-up period. The probability of discontinuation after 1, 2, and 3 years of treatment of SC MTX treatment is expected to be 6.10%, 8.50%, and 23.20%, respectively. The extrapolated median duration of SC MTX using an exponential model was 106.4 months/8.87 years. Mean dose of SC MTX was 18.36 mg. The reasons for treatment discontinuation were occurrence of adverse events in six patients and lack of efficacy in three.

Conclusion

The long treatment duration of SC MTX highlights its excellent tolerability compared to oral MTX, especially concerning the frequent adverse gastrointestinal events of MTX. Furthermore, long MTX treatment duration provides the opportunity to postpone or even avoid expensive therapies with biologics. The results obtained from the UMAR study provide important information for the utilization and public financing of SC MTX in Portugal.

     

Salvage of Malpositioned and Malfunctioning Peritoneal Dialysis Catheters by Manipulation with a Modified Malecot Introducer

Percutaneous peritoneal dialysis (PD) catheter manipulation successfully corrects displacement and contributes to catheter salvage. We describe a new device for the percutaneous treatment of malpositioned PD catheters, the modified Malecot introducer technique, which is an improvement over previous methods because its flexible consistency also allows the manipulation of swan-neck catheters. Twenty-one patients experienced catheter displacement managed by the new introducer: 12 males, average time in PD 13.7 ± 23.2 months, six with "swan-neck" catheter, seven obese, and six with previous abdominal surgery. Catheter manipulation was technically successful in 19 of 21 cases (90.4%) by the end of the first week and in 15 cases (71.4%) at 1 month. An additional eight episodes of malposition occurred ranging from 10 to 300 days after the first manipulation. A second manipulation using the same introducer was performed and resulted in long-term patency in seven patients. No complications were reported. In the long-term follow-up, only one patient removed PD catheter for mechanical dysfunction. Overall survival of manipulated catheters was 32.7 ± 23.4 months. Function at 1 month correlated with function by the first week ( r  = 0.513; p  = 0.017) and the need of a second manipulation with age ( r  = 0.494; p  = 0.027) but not with obesity or previous abdominal surgery. We conclude that manipulation using the modified Malecot introducer is a simple and effective procedure for the correction of malpositioned PD catheters. It also represents a new alternative for the management of displaced "swan-neck" catheters.     

In vitro initial immune response against Leishmania amazonensis infection is characterized by an increased production of IL-10 and IL-13

The initial encounter of Leishmania with its host's immune system is important in the outcome of infection. Previous studies have shown that PBMCs from healthy volunteers (HV) exposed to Leishmania differ in IFN-γ production. We have expanded such observations evaluating the profile and kinetics of cytokines (IFN-γ, IL-12p70, IL-10, IL-13), chemokines (CCL5, CCL3, CCL4, CXCL10), and chemokine receptors (CCR1,CCR5, CXCR3, CCR4) in vitro L. amazonensis-stimulated of HV?s PBMCs. HVs were divided in groups of high (HR) or low (LR) IFN-γ responders. In both groups, HR and LR, after L. amazonensis infection there was a predominance of IL-10 and IL-13 over IFN-γ production, while IL-12 was produced in similar amount. Regarding chemokines, a more striking difference was observed for CCL3 expression that was lower at 12 hours and 48 hours post infection in LR than in HR. Interestingly, a downregulation of CCR5 and a greater expression of CCR4 were found in low IFN-γ responders. These data suggest that early after L. amazonensis infection there is a cytokine milieu dominated by IL-13 and IL-10, and despite of this environment, IFN-γ is produced, supporting the complexity of the response. It is noteworthy that the pattern of immune response is mounted in first hours after Leishmania stimulation, with the definition of the differentiation of Th1 versus Th2 cells. It remains to be determined if such an in vitro difference has an in vivo counterpart in terms of susceptibility to infection.