Lyme borreliosis: Human impact on the peristance and circulation of Borrelia burgdorferi sensu lato in the environment

Lyme disease is a bacterial infection transmitted by hard ticks of the genus ixodes. it is primarily a zoonosis which circulates in a wide range of vertebrate hosts, wild animals (lizards, birds, rodents, dee...) and domestic animals: Humans are accidental hosts. In recent years, the notion of emergence has been raised, especiallybecause of climate changes. The reasons are more complex. The disease is better known medically: It is better diagnosed and the epidemiology is more and more understood. In addition, analysis of various biotic and abiotic factors suggests that humans impact directly the environments where ticks evolve. Indeed, for socio-economic reasons they have modified forest ecosystems and wildlife that favor the development of tick populations and consequently tick borne diseases

In vitro activity of daptomycin against Enterococcus faecalis under various conditions of growth-phases, inoculum and pH

Enterococcus faecalis (E. faecalis) has become a major leading cause of nosocomial endocarditis. Treatment of such infections remains problematic and new therapeutic options are needed. Nine E. faecalis strains were tested: six obtained from patients presenting endocarditis, one with isolated bacteremia, and two reference strains. Antibiotics included daptomycin, alone or in combination, linezolid, tigecycline, rifampicin, gentamicin, teicoplanin, ceftriaxone and amoxicillin. Time-kill studies included colony counts at 1, 4 and 24 h of incubation. Significant bactericidal activity was defined as a decrease of ≥3log10CFU/ml after 24 h of incubation. Antibiotics were tested at a low (10(6) CFU/ml) and high (10(9) CFU/ml) inoculum, against exponential- and stationary-phase bacteria. We also performed time kill studies of chemically growth arrested E. faecalis. Various pH conditions were used during the tests. In exponential growth phase and with a low inoculum, daptomycin alone at 60 µg/ml and the combination amoxicillin-gentamicin both achieved a 4-log10 reduction in one hour on all strains. In exponential growth phase with a high inoculum, daptomycin alone was bactericidal at a concentration of 120 µg/ml. All the combinations tested with this drug were indifferent. In stationary phase with a high inoculum daptomycin remained bactericidal but exhibited a pH dependent activity and slower kill rates. All combinations that did not include daptomycin were not bactericidal in conditions of high inoculum, whatever the growth phase. The results indicate that daptomycin is the only antibiotic that may be able of overcoming the effects of growth phase and high inoculum

J. Clin. Microbiol.

The use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for staphylococcal identification is now considered routine in laboratories compared with the conventional phenotypical methods previously used. We verified its microbiological relevance for identifying the main species of coagulase-negative staphylococci (CoNS) by randomly selecting 50 isolates. From 1 January 2007 to 31 August 2008, 12,479 staphylococci were isolated with phenotypic methods, of which 4,594 were identified as Staphylococcus aureus and 7,885 were coagulase negative staphylococci. Using MALDI-TOF MS from 1 January 2011 to 31 August 2012, 14,913 staphylococci were identified, with 5,066 as S. aureus and 9,847 as CoNS. MALDI-TOF MS allowed the identification of approximately 85% of the CoNS strains, whereas only 14% of the CoNS strains were identified to the species level with phenotypic methods because they were often considered contaminants. Furthermore, the use of MALDI-TOF MS revealed the occurrence of recently characterized Staphylococcus species, such as S. pettenkoferi, S. condimenti, and S. piscifermentans. Microbiological relevance analysis further revealed that some species displayed a high rate of microbiological significance, i.e., 40% of the S. lugdunensis strains included in the analysis were associated with infection risk. This retrospective microbiological study confirms the role of MALDI-TOF MS in clinical settings for the identification of staphylococci with clinical consequences. The species distribution reveals the occurrence of the recently identified species S. pettenkoferi and putative virulent species, including S. lugdunensis

黃牛與荷蘭乳牛換毛期的研究

　　生物受到外在環境極大的影響，特別是身體表面，直接左右於外在環境的部分很多，與生理變化相同、形態上的變化也很顯著。覆蓋的毛髮掌管體溫調節與保護身體的功能，各種動物會依照品種，或者是個體，各自呈現著最適合各自生存環境的狀態。因此，熱帶地區的家畜與溫帶地區的家畜有所不同是極為理所當然的自然現象。與冷熱調節關係密切、依據季節轉變的覆蓋皮毛的換毛狀態亦是如此，不難想見溫帶地區的家畜、與熱帶地區的家畜身上顯現的差異性。本論文即為溫帶產乳牛Holstein與熱帶產牛的黃牛的換毛狀態比較調查。 　　研究內容如下所述。(1)換毛通常進行於春秋二季。不過，會因為品種的不同而有時期上的差異。Holstein在春天的5月開始換毛，秋天的話在10月以後才會開始。換毛最為明顯的時期是6月。黃牛的狀況是在春天的4月，秋天的9月開始換毛。4月中旬過後、以及9月底至10月初是換毛最為明顯的時期。這個換毛狀態也會因為不同個體而有些許的差異性。(2)除了春秋二季的定期換毛以外，每個月多少都會有一些換毛。將新生毛的比例加以平均的話，則可知Holstein在6月有34％，7月有12％，8月有31％的程度。黃牛則是在6月有12％，7月有16％，8月有26％這樣的程度。(3)只要換成夏毛的話，則其中不會混有冬毛。(4)覆蓋毛髮因應氣溫變化而有長度與粗細的不同，冬天細長，夏天粗短。(5) Holstein與黃牛互相比較，則換毛的顯著時期較遲。這是因為在因應氣候的方面，Holstein的反應程度比黃牛來得低。(6)一般而言，夏毛的生存期比冬毛短，夏毛在經過約略5個月之後轉為冬毛，而冬毛則是經過約略7個月後轉為夏毛。(7)髓質在夏天的時候不太發達。封面、書名頁、印記、目次頁 I　緒言 II　研究材料並ニ研究方法 　A）供試動物 　B）供試動物ノ飼養管理 　　i）黄牛ノ状態 　　ii）ホルスタインノ状態 　C）試驗期間及ビ採毛期日 　D）採毛方法 　E）調査方法 III　實驗結果 IV　實驗結果ノ觀察 　A）ホルスタイン 　B）黄牛 　C）ホルスタイント黄牛ノ比較 V　結論 VI　摘要 参【參】考文献 圖表 　（一） 　（二） 圖版、印記、封

BMC Infect. Dis.

BACKGROUND: Interpretation of serological assays in Lyme borreliosis requires an understanding of the clinical indications and the limitations of the currently available tests. We therefore systematically reviewed the accuracy of serological tests for the diagnosis of Lyme borreliosis in Europe. METHODS: We searched EMBASE en MEDLINE and contacted experts. Studies evaluating the diagnostic accuracy of serological assays for Lyme borreliosis in Europe were eligible. Study selection and data-extraction were done by two authors independently. We assessed study quality using the QUADAS-2 checklist. We used a hierarchical summary ROC meta-regression method for the meta-analyses. Potential sources of heterogeneity were test-type, commercial or in-house, Ig-type, antigen type and study quality. These were added as covariates to the model, to assess their effect on test accuracy. RESULTS: Seventy-eight studies evaluating an Enzyme-Linked ImmunoSorbent assay (ELISA) or an immunoblot assay against a reference standard of clinical criteria were included. None of the studies had low risk of bias for all QUADAS-2 domains. Sensitivity was highly heterogeneous, with summary estimates: erythema migrans 50 % (95 % CI 40 % to 61 %); neuroborreliosis 77 % (95 % CI 67 % to 85 %); acrodermatitis chronica atrophicans 97 % (95 % CI 94 % to 99 %); unspecified Lyme borreliosis 73 % (95 % CI 53 % to 87 %). Specificity was around 95 % in studies with healthy controls, but around 80 % in cross-sectional studies. Two-tiered algorithms or antibody indices did not outperform single test approaches. CONCLUSIONS: The observed heterogeneity and risk of bias complicate the extrapolation of our results to clinical practice. The usefulness of the serological tests for Lyme disease depends on the pre-test probability and subsequent predictive values in the setting where the tests are being used. Future diagnostic accuracy studies should be prospectively planned cross-sectional studies, done in settings where the test will be used in practice

Assessment of MALDI-TOF MS biotyping for Borrelia burgdorferi sl detection in Ixodes ricinus.

Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been demonstrated to be useful for tick identification at the species level. More recently, this tool has been successfully applied for the detection of bacterial pathogens directly in tick vectors. The present work has assessed the detection of Borrelia burgdorferi sensu lato in Ixodes ricinus tick vector by MALDI-TOF MS. To this aim, experimental infection model of I. ricinus ticks by B. afzelii was carried out and specimens collected in the field were also included in the study. Borrelia infectious status of I. ricinus ticks was molecularly controlled using half-idiosome to classify specimens. Among the 39 ticks engorged on infected mice, 14 were confirmed to be infected by B. afzelii. For field collection, 14.8% (n = 12/81) I. ricinus ticks were validated molecularly as infected by B. burgdorferi sl. To determine the body part allowing the detection of MS protein profile changes between non-infected and B. afzelii infected specimens, ticks were dissected in three compartments (i.e. 4 legs, capitulum and half-idiosome) prior to MS analysis. Highly reproducible MS spectra were obtained for I. ricinus ticks according to the compartment tested and their infectious status. However, no MS profile change was found when paired body part comparison between non-infected and B. afzelii infected specimens was made. Statistical analyses did not succeed to discover, per body part, specific MS peaks distinguishing Borrelia-infected from non-infected ticks whatever their origins, laboratory reared or field collected. Despite the unsuccessful of MALDI-TOF MS to classify tick specimens according to their B. afzelii infectious status, this proteomic tool remains a promising method for rapid, economic and accurate identification of tick species. Moreover, the singularity of MS spectra between legs and half-idiosome of I. ricinus could be used to reinforce this proteomic identification by submission of both these compartments to MS