305 research outputs found

    Emergence and Evolution of Multidrug-Resistant Klebsiella pneumoniae with both blaKPC and blaCTX-M Integrated in the Chromosome

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    The extended-spectrum-β-lactamase (ESBL)- and Klebsiella pneumoniaecarbapenemase (KPC)-producing Enterobacteriaceae represent serious and urgent threats to public health. In a retrospective study of multidrug-resistant K. pneumoniae, we identified three clinical isolates, CN1, CR14, and NY9, carrying both blaCTX-M and blaKPC genes. The complete genomes of these three K. pneumoniae isolates were de novo assembled by using both short- and long-read whole-genome sequencing. In CR14 and NY9, blaCTX-M and blaKPC were carried on two different plasmids. In contrast, CN1 had one copy of blaKPC-2 and three copies of blaCTX-M-15 integrated in the chromosome, for which the blaCTX-M-15 genes were linked to an insertion sequence, ISEcp1, whereas the blaKPC-2 gene was in the context of a Tn4401a transposition unit conjugated with a PsP3-like prophage. Intriguingly, downstream of the Tn4401a-blaKPC-2-prophage genomic island, CN1 also carried a clustered regularly interspaced short palindromic repeat (CRISPR)-cas array with four spacers targeting a variety of K. pneumoniae plasmids harboring antimicrobial resistance genes. Comparative genomic analysis revealed that there were two subtypes of type I-E CRISPR-cas in K. pneumoniae strains and suggested that the evolving CRISPR-cas, with its acquired novel spacer, induced the mobilization of antimicrobial resistance genes from plasmids into the chromosome. The integration and dissemination of multiple copies of blaCTX-Mand blaKPC from plasmids to chromosome depicts the complex pandemic scenario of multidrug-resistant K. pneumoniae. Additionally, the implications from this study also raise concerns for the application of a CRISPR-cas strategy against antimicrobial resistance

    Immunoblot analysis of the seroreactivity to recombinant Borrelia burgdorferi sensu lato antigens, including VlsE, in the long-term course of treated patients with Erythema migrans

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    Objective: We evaluated whether immunoblotting is capable of substantiating the posttreatment clinical assessment of patients with erythema migrans ( EM), the hallmark of early Lyme borreliosis. Methods: In 50 patients, seroreactivity to different antigens of Borrelia burgdorferi sensu lato was analyzed by a recombinant immunoblot test (IB) in consecutive serum samples from a minimum follow-up period of 1 year. Antigens in the IgG test were decorin- binding protein A, internal fragment of p41 (p41i), outer surface protein C (OspC), p39, variable major protein-like sequence expressed (VlsE), p58 and p100; those in the IgM test were p41i, OspC and p39. Immune responses were correlated with clinical and treatment-related parameters. Results: Positive IB results were found in 50% before, in 57% directly after therapy and in 44% by the end of the follow-up for the IgG class, and in 36, 43 and 12% for the IgM class. In acute and convalescence phase sera, VlsE was most immunogenic on IgG testing 60 and 70%), and p41i (46 and 57%) and OspC (40 and 57%) for the IgM class. By the end of the follow-up, only the anti-p41i lgM response was significantly decreased to 24%. Conclusions: No correlation was found between IB results and treatment-related parameters. Thus, immunoblotting does not add to the clinical assessment of EM patients after treatment. Copyright (c) 2008 S. Karger AG, Basel

    Early Lyme disease with spirochetemia - diagnosed by DNA sequencing

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    <p>Abstract</p> <p>Background</p> <p>A sensitive and analytically specific nucleic acid amplification test (NAAT) is valuable in confirming the diagnosis of early Lyme disease at the stage of spirochetemia.</p> <p>Findings</p> <p>Venous blood drawn from patients with clinical presentations of Lyme disease was tested for the standard 2-tier screen and Western Blot serology assay for Lyme disease, and also by a nested polymerase chain reaction (PCR) for <it>B. burgdorferi </it>sensu lato 16S ribosomal DNA. The PCR amplicon was sequenced for <it>B. burgdorferi </it>genomic DNA validation. A total of 130 patients visiting emergency room (ER) or Walk-in clinic (WALKIN), and 333 patients referred through the private physicians' offices were studied. While 5.4% of the ER/WALKIN patients showed DNA evidence of spirochetemia, none (0%) of the patients referred from private physicians' offices were DNA-positive. In contrast, while 8.4% of the patients referred from private physicians' offices were positive for the 2-tier Lyme serology assay, only 1.5% of the ER/WALKIN patients were positive for this antibody test. The 2-tier serology assay missed 85.7% of the cases of early Lyme disease with spirochetemia. The latter diagnosis was confirmed by DNA sequencing.</p> <p>Conclusion</p> <p>Nested PCR followed by automated DNA sequencing is a valuable supplement to the standard 2-tier antibody assay in the diagnosis of early Lyme disease with spirochetemia. The best time to test for Lyme spirochetemia is when the patients living in the Lyme disease endemic areas develop unexplained symptoms or clinical manifestations that are consistent with Lyme disease early in the course of their illness.</p

    Diagnostic challenges of early Lyme disease: Lessons from a community case series

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    <p>Abstract</p> <p>Background</p> <p>Lyme disease, the most common vector-borne infection in North America, is increasingly reported. When the characteristic rash, erythema migrans, is not recognized and treated, delayed manifestations of disseminated infection may occur. The accuracy of diagnosis and treatment of early Lyme disease in the community is unknown.</p> <p>Methods</p> <p>A retrospective, consecutive case series of 165 patients presenting for possible early Lyme disease between August 1, 2002 and August 1, 2007 to a community-based Lyme referral practice in Maryland. All patients had acute symptoms of less than or equal to 12 weeks duration. Patients were categorized according to the Centers for Disease Control and Prevention criteria and data were collected on presenting history, physical findings, laboratory serology, prior diagnoses and prior treatments.</p> <p>Results</p> <p>The majority (61%) of patients in this case series were diagnosed with early Lyme disease. Of those diagnosed with early Lyme disease, 13% did not present with erythema migrans; of those not presenting with a rash, 54% had been previously misdiagnosed. Among those with a rash, the diagnosis of erythema migrans was initially missed in 23% of patients whose rash was subsequently confirmed. Of all patients previously misdiagnosed, 41% had received initial antibiotics likely to be ineffective against Lyme disease.</p> <p>Conclusion</p> <p>For community physicians practicing in high-risk geographic areas, the diagnosis of Lyme disease remains a challenge. Failure to recognize erythema migrans or alternatively, viral-like presentations without a rash, can lead to missed or delayed diagnosis of Lyme disease, ineffective antibiotic treatment, and the potential for late manifestations.</p

    Health care costs, utilization and patterns of care following Lyme disease

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    BACKGROUND:Lyme disease is the most frequently reported vector borne infection in the United States. The Centers for Disease Control have estimated that approximately 10% to 20% of individuals may experience Post-Treatment Lyme Disease Syndrome - a set of symptoms including fatigue, musculoskeletal pain, and neurocognitive complaints that persist after initial antibiotic treatment of Lyme disease. Little is known about the impact of Lyme disease or post-treatment Lyme disease symptoms (PTLDS) on health care costs and utilization in the United States. OBJECTIVES:1) to examine the impact of Lyme disease on health care costs and utilization, 2) to understand the relationship between Lyme disease and the probability of developing PTLDS, 3) to understand how PTLDS may impact health care costs and utilization. METHODS:This study utilizes retrospective data on medical claims and member enrollment for persons aged 0-64 years who were enrolled in commercial health insurance plans in the United States between 2006-2010. 52,795 individuals treated for Lyme disease were compared to 263,975 matched controls with no evidence of Lyme disease exposure. RESULTS:Lyme disease is associated with 2,968highertotalhealthcarecosts(952,968 higher total health care costs (95% CI: 2,807-3,128, p<.001) and 87% more outpatient visits (95% CI: 86%-89%, p<.001) over a 12-month period, and is associated with 4.77 times greater odds of having any PTLDS-related diagnosis, as compared to controls (95% CI: 4.67-4.87, p<.001). Among those with Lyme disease, having one or more PTLDS-related diagnosis is associated with 3,798 higher total health care costs (95% CI: 3,542-4,055, p<.001) and 66% more outpatient visits (95% CI: 64%-69%, p<.001) over a 12-month period, relative to those with no PTLDS-related diagnoses. CONCLUSIONS:Lyme disease is associated with increased costs above what would be expected for an easy to treat infection. The presence of PTLDS-related diagnoses after treatment is associated with significant health care costs and utilization

    Simple Objective Detection of Human Lyme Disease Infection Using Immuno-PCR and a Single Recombinant Hybrid Antigen

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    A serology-based tiered approach has, to date, provided the most effective means of laboratory confirmation of clinically suspected cases of Lyme disease, but it lacks sensitivity in the early stages of disease and is often dependent on subjectively scored immunoblots. We recently demonstrated the use of immuno-PCR (iPCR) for detecting Borrelia burgdorferi antibodies in patient serum samples that were positive for Lyme disease. To better understand the performance of the Lyme disease iPCR assay, the repeatability and variability of the background of the assay across samples from a healthy population (n = 36) were analyzed. Both of these parameters were found to have coefficients of variation of \u3c 3%. Using eight antigen-specific iPCR assays and positive call thresholds established for each assay, iPCR IgM and/or IgG diagnosis from Lyme disease patient serum samples (n = 12) demonstrated a strong correlation with that of 2-tier testing. Furthermore, a simplified iPCR approach using a single hybrid antigen and detecting only IgG antibodies confirmed the 2-tier diagnosis in the Lyme disease patient serum samples (n = 12). Validation of the hybrid antigen IgG iPCR assay using a blinded panel of Lyme disease and non-Lyme disease patient serum samples (n = 92) resulted in a sensitivity of 69% (95% confidence interval [CI], 50% to 84%), compared to that of the 2-tier analysis at 59% (95% CI, 41% to 76%), and a specificity of 98% (95% CI, 91% to 100%) compared to that of the 2-tier analysis at 97% (95% CI, 88% to 100%). A single-tier hybrid antigen iPCR assay has the potential to be an improved method for detecting host-generated antibodies against B. burgdorferi
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