SummaryBackgroundTraditional methods for molecular epidemiology of Neisseria gonorrhoeae are suboptimal. Whole-genome sequencing (WGS) offers ideal resolution to describe population dynamics and to predict and infer transmission of antimicrobial resistance, and can enhance infection control through linkage with epidemiological data. We used WGS, in conjunction with linked epidemiological and phenotypic data, to describe the gonococcal population in 20 European countries. We aimed to detail changes in phenotypic antimicrobial resistance levels (and the reasons for these changes) and strain distribution (with a focus on antimicrobial resistance strains in risk groups), and to predict antimicrobial resistance from WGS data.MethodsWe carried out an observational study, in which we sequenced isolates taken from patients with gonorrhoea from the European Gonococcal Antimicrobial Surveillance Programme in 20 countries from September to November, 2013. We also developed a web platform that we used for automated antimicrobial resistance prediction, molecular typing (N gonorrhoeae multi-antigen sequence typing [NG-MAST] and multilocus sequence typing), and phylogenetic clustering in conjunction with epidemiological and phenotypic data.FindingsThe multidrug-resistant NG-MAST genogroup G1407 was predominant and accounted for the most cephalosporin resistance, but the prevalence of this genogroup decreased from 248 (23%) of 1066 isolates in a previous study from 2009–10 to 174 (17%) of 1054 isolates in this survey in 2013. This genogroup previously showed an association with men who have sex with men, but changed to an association with heterosexual people (odds ratio=4·29). WGS provided substantially improved resolution and accuracy over NG-MAST and multilocus sequence typing, predicted antimicrobial resistance relatively well, and identified discrepant isolates, mixed infections or contaminants, and multidrug-resistant clades linked to risk groups.InterpretationTo our knowledge, we provide the first use of joint analysis of WGS and epidemiological data in an international programme for regional surveillance of sexually transmitted infections. WGS provided enhanced understanding of the distribution of antimicrobial resistance clones, including replacement with clones that were more susceptible to antimicrobials, in several risk groups nationally and regionally. We provide a framework for genomic surveillance of gonococci through standardised sampling, use of WGS, and a shared information architecture for interpretation and dissemination by use of open access software.FundingThe European Centre for Disease Prevention and Control, The Centre for Genomic Pathogen Surveillance, Örebro University Hospital, and Wellcome.
NG-monomethylarginine (L-NMA) and asymmetric NG, NG-dimethylarginines (ADMA) are endogenous inhibitors of cellular L-arginine uptake and/or nitric oxide (NO) synthesis that are implicated in renal parenchymal and Dahl salt-sensitive hypertension. Since the L-arginine:(L-NMA + ADMA) ratio determines NO synthase (NOS) activity, we compared the immunohistochemical distribution of NOS with NG, NG-dimethylarginine dimethylaminohydrolase (DDAH), which inactivates dimethylarginines (DMA) and L-NMA by hydrolysis to L-citrulline. Neuronal NOS (nNOS) was expressed predominantly in tubular epithelial cells of macula densa (MD), endothelial NOS (eNOS) in vascular endothelial cells (EC), and inducible NOS (iNOS) quite widely in tubular epithelium, including proximal tubules (PT), thick ascending limbs of Henle (TAL), distal convoluted tubule and intercalated cells (IC) of the collecting duct. Immunostaining for DDAH was present in PT, TAL, MD, and IC, and was also present in the glomerulus, Bowman's capsule, and endothelium of blood vessels. DDAH was detected in small vesicles of TAL and PT by electron microscopic (EM) immunocytochemistry. To study the effects of methylarginines on tubuloglomerular feedback (TGF) response, vehicle or methylarginines (10(-3) M) were added to artificial tubular fluid (ATF) perfused orthogradely from the late PT at 40 nl. min-1 while assessing changes in glomerular capillary pressure from proximal stop flow pressure (PSF). Whereas the maximal TGF responses were unchanged by vehicle (delta TGF 0 +/- 0%) or symmetric DMA (SDMA; +1 +/- 2%, NS), they were enhanced by L-NMA (+22 +/- 4%, P < 0.001) and asymmetric DMA (ADMA; +28 +/- 3%, P < 0.001). Since L-arginine transport can regulate renal epithelial NO generation, methylarginines (10(-3) M) or vehicle were co-perfused orthogradely with [3H]-L-arginine from the late PT and collected at the early distal tubule to study arginine uptake from the perfused loop of Henle. All methylarginines reduced fractional loop [3H] absorption significantly (P < 0.001; vehicle, 84 +/- 6; ADMA, 49 +/- 6; SDMA, 56 +/- 6; L-NMA, 41 +/- 6%). In conclusion, sites of DDAH expression in the vasculature or nephron are all sites of expression of an isoform of NOS. L-NMA, ADMA, and SDMA all inhibit renal tubular L-arginine uptake, whereas L-NMA and ADMA, but not SDMA, enhance TGF responses. Therefore, DDAH may regulate the cellular L-arginine: methylarginine levels in specific renal cells, thereby governing cell-specific L-arginine uptake and NO generation in renal tubular epithelium.
Background: Men who have sex with men (MSM) are disproportionally affected by sexually transmitted infections (STI). STI are often extragenital and asymptomatic. Both can delay diagnosis and treatment. Approval of HIV preexposure prophylaxis (PrEP) might have influenced sexual behaviour and STI-prevalence of HIV-MSM. We estimated STI-prevalence and risk factors amongst HIV-and HIV+ MSM in Germany to plan effective interventions. Methods: We conducted a nationwide, cross-sectional study between February and July 2018. Thirteen MSMfriendly STI-practices screened MSM for Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhea (NG), and Trichomonas vaginalis (TV) using self-collected rectal and pharyngeal swabs, and urine samples. APTIMA™ STI-assays (Hologic™ Inc., San Diego, USA) were used for diagnostics, and samples were not pooled. We collected information on socio-demographics, HIV-status, clinical symptoms, sexual behaviour within the last 6 months, and PrEP use. We combined HIV status and PrEP use for defining risk groups, and used directed acyclic graphs and multivariable logistic regression to identify risk factors for STI. Results: Two thousand three hundred three MSM were included: 50.5% HIV+, median age 39 [18-79] years. Median number of male sex partners within the last 6 months was five. Sex without condom was reported by 73.6%, use of party drugs by 44.6%. 80.3% had a STI history, 32.2% of STI+ MSM reported STI-related symptoms. 27.6% of HIV-MSM used PrEP.
Bakterielle sexuell übertragbare Infektionen (STI) zeigen seit Jahren weltweit eine deutliche Zunahme. In Deutschland wird diese Tatsache durch steigende Meldezahlen für Syphilis bestätigt. Auch für die nicht meldepflichtigen STI Gonorrhoe, Chlamydia-trachomatisund Mycoplasma-genitalium -Infektionen wird eine zunehmende Inzidenz beobachtet. Entscheidend für die Weiterverbreitung ist, dass das breite klinische Spektrum, welches neben Urogenitalsitus auch Pharynx und Rektum einbezieht, durch eine hohe Zahl asymptomatischer Verläufe ergänzt wird. Neue Real-Time-Multiplex-Diagnostikverfahren ermöglichen einen schnellen und gezielten Nachweis von STI-Erregern. Die häufigste bakterielle STI ist die urogenitale Chlamydieninfektion mit den Serovaren D-K, die besonders bei jungen Erwachsenen auftritt. Einer Chlamydien-Proktitis kann eine Infektion mit L-Serovaren und damit eine Lymphogranuloma-venereum (LGV)-Infektion zugrunde liegen. Neisseria (N.) gonorrhoeae zeigte in den letzten Jahren eine starke Resistenzentwicklung mit Ausbildung von Einzel-und Multiresistenzen gegenüber bisher gängigen Antibiotika. Daher ist für N. gonorrhoeae zusätzlich zum nucleic acid amplification test (NAAT) eine kulturelle Empfindlichkeitstestung durchzuführen. Auch für Mycoplasma genitalium sind Resistenzentwicklungen bekannt, die eine Therapie erschweren können.
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