Synthetic mRNA delivered to human cells leads to expression of Cpl-1 bacteriophage-endolysin with activity against Streptococcus pneumoniae.

Endolysins are bacteriophage-encoded hydrolases that show high antibacterial activity and a narrow substrate spectrum. We hypothesize that an mRNA-based approach to endolysin therapy can overcome some challenges of conventional endolysin therapy, namely organ targeting and bioavailability. We show that synthetic mRNA applied to three human cell lines (HEK293T, A549, HepG2 cells) leads to expression and cytosolic accumulation of the Cpl-1 endolysin with activity against Streptococcus pneumoniae. Addition of a human lysozyme signal peptide sequence translocates the Cpl-1 to the endoplasmic reticulum leading to secretion (hlySP-sCpl-1). The pneumococcal killing effect of hlySP-sCpl-1 was enhanced by introduction of a point mutation to avoid N-linked-glycosylation. hlySP-sCpl-1N215D, collected from the culture supernatant of A549 cells 6 h post-transfection showed a significant killing effect and was active against nine pneumococcal strains. mRNA-based cytosolic Cpl-1 and secretory hlySP-sCpl-1N215D show potential for innovative treatment strategies against pneumococcal disease and, to our best knowledge, represent the first approach to mRNA-based endolysin therapy. We assume that many other bacterial pathogens could be targeted with this novel approach.

The effect of temperature, humidity, precipitation and cloud coverage on the risk of COVID-19 infection in temperate regions of the USA-A case-crossover study.

BACKGROUND: Observations based on the spread of SARS-CoV-2 early into the COVID-19 pandemic have suggested a reduced burden in tropical regions leading to the assumption of a dichotomy between cold and dry and wet and warm climates. OBJECTIVES: Analyzing more than a whole year of COVID-19 infection data, this study intents to refine the understanding of meteorological variables (temperature, humidity, precipitation and cloud coverage) on COVID-19 transmission in settings that experience distinct seasonal changes. METHODS AND FINDINGS: A time stratified case-crossover design was adopted with a conditional Poisson model in combination with a distributed lag nonlinear model to assess the short-term impact of mentioned meteorological factors on COVID-19 infections in five US study sites (New York City (NYC); Marion County, Indiana (MCI); Baltimore and Baltimore County, Maryland (BCM); Franklin County, Ohio (FCO); King County, Washington (KCW)). Higher-than-average temperatures were consistently associated with a decreased relative risk (RR) of COVID-19 infection in four study sites. At 20 degrees Celsius COVID-19 infection was associated with a relative risk of 0.35 (95%CI: 0.20-0.60) in NYC, 1.03 (95%CI:0.57-1.84) in MCI, 0.34 (95%CI: 0.20-0.57) in BCM, 0.52 (95%CI: 0.31-0.87) in FCO and 0.21 (95%CI: 0.10-0.44) in KCW. Higher-than-average humidity levels were associated with an increased relative risk of COVID-19 infection in four study sites. Relative to their respective means, at a humidity level of 15 g/kg (specific humidity) the RR was 5.83 (95%CI: 2.05-16.58) in BCM, at a humidity level of 10 g/kg the RR was 3.44 (95%CI: 1.95-6.01) in KCW. CONCLUSIONS: The results of this study suggest opposed effects for higher-than-average temperature and humidity concerning the risk of COVID-19 infection. While a distinct seasonal pattern of COVID-19 has not yet emerged, warm and humid weather should not be generally regarded as a time of reduced risk of COVID-19 infections.

Parvimonas parva sp. nov., derived from a human genito-urinary lesion.

A strain of obligately anaerobically growing Gram-positive cocci was isolated from a human genito-urinary sample and characterized by a polyphasic approach. Analyses of 16S rRNA gene and whole-genome sequences of this strain S3374T indicated that it belonged to the genus Parvimonas. Overall genome relatedness index calculations confirmed it to be phylogenetically distinct from Parvimonas micra (NCTC 11808T) as its most closely related species with standing in nomenclature, with average nucleotide identity and genome-to-genome distance values of 85.8 and 30.2 %, respectively. Biochemically, strain S3374T was strongly proteolytic and can be differentiated from P. micra (DSM 20468T) by absence of phosphatase activity. The DNA G+C content of strain S3374T was 28.6 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3374T is considered to represent a novel species within the genus Parvimonas, for which the name Parvimonas parva sp. nov. is proposed. The type strain is S3374T (=DSM 110786T=CCOS 1934T=CCUG 74294T). This description adds strain S3374T as a second species to the genus Parvimonas which has so far been monotypic. While the type strain of this genus, P. micra, has a long standing in nomenclature and its role in human health and disease has been studied to some extent, this description of the proposed novel species represented by strain S3374T will allow microbiologists worldwide to identify isolates of P. parva sp. nov., a prerequisite for further investigation of its relevance in the clinical context and beyond.

Eikenella glucosivorans sp. nov., isolated from a human throat swab, and emendation of the genus Eikenella to include saccharolytic species.

A novel species within the genus Eikenella is described, based on the phenotypical, biochemical and genetic characterization of a strain of a facultatively anaerobic, Gram-negative rod-shaped bacterium. Strain S3360T was isolated from the throat swab of a patient sampled during routine care at a hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequences) placed the strain in the genus Eikenella, separate from all recognized species but with the closest relationship to Eikenella longinqua (NML 02-A-017T). Eikenella is one of the genera in the HACEK group known to be responsible for rare cases of endocarditis in humans. Until the recent descriptions of Eikenella exigua, Eikenella halliae and Eikenella longinqua, Eikenella corrodens had been the only validly published species in this genus since its description as Bacteroides corrodens in 1958. Unlike these species, strain S3360T is able to metabolize carbohydrates (glucose). The average nucleotide identities of strain S3360T with E. longinqua (NML 02-A-017T) and E. corrodens (NCTC 10596T), the type species of the genus, were 90.5 and 84.7 %, respectively, and the corresponding genome-to-genome distance values were 41.3 and 29.0 %, respectively. The DNA G+C content of strain S3360T was 58.4 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3360T is considered to represent a novel species within the genus Eikenella, for which the name Eikenella glucosivorans sp. nov. is proposed. The type strain is S3360T (DSM 110714T=CCOS 1935T=CCUG 74293T). In addition, an emendation of the genus Eikenella is proposed to include species which are saccharolytic.

Tuberculosis and Takayasu arteritis: case-based review.

This report presents a case of co-occurrence of Takayasu arteritis (TA) and multiorgan tuberculosis (TB) in a 20-year-old female and provides a review of 18 previously reported cases of co-occurring TA and TB. All patients were between 9 and 24 years of age. Most reports describe a concomitant diagnosis of active TB and TA. TB lymphadenitis was described in 11 cases (57.9%), and microbiologically confirmed in 4 of these. All patients received antituberculous therapy and most received corticosteroids (89.5%). In our and two other cases, TA relapses necessitating additional immunosuppressive therapy were observed.

Whole-body Magnetic Resonance Imaging in Chronic Recurrent Multifocal Osteomyelitis: Clinical Longterm Assessment May Underestimate Activity.

OBJECTIVE: (1) To examine how many patients have clinically and/or radiologically active chronic recurrent multifocal osteomyelitis (CRMO) ≥ 10 years after first onset of symptoms, and (2) to compare clinical and whole-body magnetic resonance imaging (WB-MRI) findings. METHODS: Seventeen patients (82% women) who were diagnosed with childhood-onset CRMO at least 10 years (average 12) before reexamination were reevaluated. Patients completed a standardized questionnaire, and underwent clinical and laboratory investigation and WB-MRI. Clinical features were compared with imaging findings. RESULTS: Five patients were found to be in clinical and radiological remission. One of these patients demonstrated 1 radiologically inactive lesion on WB-MRI. Four patients showed radiologically active lesions despite full clinical remission, 2 of them in 3 vertebral bodies. Spinal involvement in 6 patients (35%) caused vertebral compression fractures, vertebra plana, or vertebral hemifusion. Eight patients presented with ongoing clinical disease activity. When applying a CRMO activity score based on clinical and imaging findings, 2 patients were identified as having pain amplification. Overall, 22/55 known CRMO lesions were identified; 11 of them were radiologically active lesions. Additionally, 14 so far unknown clinically silent lesions were detected: 8 radiologically active lesions and 6 radiologically inactive lesions. CONCLUSION: CRMO activity on longterm followup might have been underestimated. Our study demonstrates that clinical remission does not necessarily mean radiological remission. We therefore propose that all patients with CRMO, including patients in clinical remission, require longterm clinical followup and should undergo evaluation with WB-MRI on a regular basis until radiological remission or a steady state of disease is achieved.