The effect of COVID-19 vaccination on 30-day mortality after cardiac surgery - Insights from the Israel national registries.

Background: We compared the effect of perioperative COVID-19, before and after vaccination, on 30-day mortality after cardiac surgery. Methods: Data was extracted from several national registries. The study period was March 1st, 2020-March 31st, 2022. Results: 2594 adult patients underwent cardiac surgery before the availability of a universal COVID-19 vaccine. 33 patients were diagnosed with COVID-19 prior to surgery (mean age 58.3±10.0, mean length of time 73.6±60.1 days) and 7 patients were diagnosed with COVID-19 0-14 days after surgery (age 66.4±7.6). These were compared to 4426 patients who underwent cardiac surgery after the availability of a universal vaccine: 469 patients were diagnosed with COVID-19 prior to surgery (age 62.1±10.1, length of time 175.8±158.2) and 32 patients diagnosed with COVID-19 0-14 days after surgery (age 60.8±14.5). In patients diagnosed with COVID-19 prior to surgery, there was no excess 30-day mortality either before or after vaccination (1 (3.0%) vs. 57 (2.2%), respectively, P<0.8, and 8 (1.7%) vs. 87 (2.2%), respectively, P<0.5). Patients diagnosed with COVID-19 after surgery, but before vaccination, had significantly higher 30-day mortality compared to COVID-19 negative patients (2 (28.6%) vs. 56 (2.2%) respectively, P<0.0001). This excess mortality disappeared after universal vaccination (1 (3.1%) vs. 94 (2.1%) respectively, P<0.7). Conclusions: COVID-19, when diagnosed in the early post-operative period, was a risk factor for mortality before available vaccinations, but not after vaccination was widely available. Pre-surgery screening and post-surgical isolation is essential until vaccines are available. This data may be useful for patient management in future respiratory pandemics.

Differential contribution of Clavibacter michiganensis ssp. michiganensis virulence factors to systemic and local infection in tomato.

Clavibacter michiganensis ssp. michiganensis (Cmm) causes substantial economic losses in tomato production worldwide. The disease symptoms observed in plants infected systemically by Cmm are wilting and canker on the stem, whereas blister-like spots develop in locally infected leaves. A wide repertoire of serine proteases and cell wall-degrading enzymes has been implicated in the development of wilt and canker symptoms. However, virulence factors involved in the formation of blister-like spots, which play an important role in Cmm secondary spread in tomato nurseries, are largely unknown. Here, we demonstrate that Cmm virulence factors play different roles during blister formation relative to wilting. Inoculation with a green fluorescent protein (GFP)-labelled Cmm382 indicates that penetration occurs mainly through trichomes. When spray inoculated on tomato leaves, the wild-type Cmm382 and Cmm100 (lacking plasmids pCM1 and pCM2) strains form blister-like spots on leaves, whereas Cmm27 (lacking the chp/tomA pathogenicity island) is non-pathogenic, indicating that plasmid-borne genes, which have a crucial role in wilting, are not required for blister formation. Conversely, mutations in chromosomal genes encoding serine proteases (chpC and sbtA), cell wall-degrading enzymes (pgaA and endX/Y), a transcriptional regulator (vatr2), a putative perforin (perF) and a putative sortase (srtA) significantly affect disease incidence and the severity of blister formation. The transcript levels of these genes, as measured by quantitative reverse transcription-polymerase chain reaction, showed that, during blister formation, they are expressed early at 8-16 h after inoculation, whereas, during wilting, they are expressed after 24-72 h or expressed at low levels. Plant gene expression studies suggest that chpC is involved in the suppression of host defence.

Virulence and in planta movement of Xanthomonas hortorum pv. pelargonii are affected by the diffusible signal factor (DSF)-dependent quorum sensing system.

Xanthomonas hortorum pv. pelargonii (Xhp), the causal agent of bacterial blight in pelargonium, is the most threatening bacterial disease of this ornamental worldwide. To gain an insight into the regulation of virulence in Xhp, we have disrupted the quorum sensing (QS) genes, which mediate the biosynthesis and sensing of the diffusible signal factor (DSF). Mutations in rpfF (encoding the DSF synthase) and rpfC (encoding the histidine sensor kinase of the two-component system RfpC/RpfG) and overexpression of rpfF showed a significant reduction in incidence and severity of the disease on pelargonium. Confocal laser scanning microscopy images of inoculated plants with a green fluorescent protein (GFP)-labelled wild-type strain showed that the pathogen is homogeneously dispersed in the lumen of xylem vessels, reaching the apex and invading the intercellular spaces of the leaf mesophyll tissue within 21 days. In contrast, the rpfF and rpfC knockout mutants, as well as the rpfF-overexpressing strain, remained confined to the vicinity of the inoculation site. The rpfF and rpfC mutants formed large incoherent aggregates in the xylem vessels that might interfere with upward movement of the bacterium within the plant. Both mutants also formed extended aggregates under in vitro conditions, whereas the wild-type strain formed microcolonies. Expression levels of putative virulence genes in planta were substantially reduced within 48 h after inoculation with the QS mutants when compared with the wild-type. The results presented indicate that an optimal DSF concentration is crucial for successful colonization and virulence of Xhp in pelargonium.

Effect of calibration method on distortion-product otoacoustic emission measurements at and around 4 kHz.

OBJECTIVES: Distortion-product otoacoustic emissions (DPOAEs) collected after sound pressure level (SPL) calibration are susceptible to standing waves that affect measurements at the plane of the probe microphone due to overlap of incident and reflected waves. These standing-wave effects can be as large as 20 dB, and may affect frequencies both above and below 4 kHz. It has been shown that forward pressure level (FPL) calibration minimizes standing-wave effects by isolating the forward-propagating component of the stimulus. Yet, previous work has failed to demonstrate more than a small difference in test performance and behavioral-threshold prediction with DPOAEs after SPL and FPL calibration. One potential limitation in prior studies is that measurements were restricted to octave and interoctave frequencies; as a consequence, data were not necessarily collected at the standing-wave null frequency. In the present study, DPOAE responses were measured with f2 set to each participant's standing-wave frequency in an effort to increase the possibility that differences in test performance and threshold prediction would be observed for SPL and FPL calibration methods. DESIGN: Data were collected from 42 normal-hearing participants and 93 participants with hearing loss. DPOAEs were measured with f2 set to 4 kHz and at each participant's notch frequency after SPL and FPL calibration. DPOAE input/output functions were obtained from -10 to 80 dB in 5 dB steps for each calibration/stimulus condition. Test performance was evaluated using clinical decision theory. Both area under receiver operating characteristic curves for all stimulus levels and cumulative distributions when L2 = 50 dB (a level at which the best performance was observed regardless of calibration method) were used to evaluate the accuracy with which auditory status was determined. A bootstrap procedure was used to evaluate the significance of the differences in test performance between SPL and FPL calibrations. DPOAE predictions of behavioral threshold were evaluated by correlating actual behavioral thresholds and predicted thresholds using a multiple linear regression model. RESULTS: First, larger DPOAE levels were measured after SPL calibration than after FPL calibration, which demonstrated the expected impact of standing waves. Second, for both FPL and SPL calibration, test performance was best for moderate stimulus levels. Third, differences in test performance between calibration methods were evident at low- and high-stimulus levels. Fourth, there were small but statistically significant improvements in test performance after FPL calibration for clinically relevant conditions. Fifth, calibration method had no effect on threshold prediction. CONCLUSIONS: Standing waves after SPL calibration have an impact on DPOAE levels. Although the effect of calibration method on test performance was small, test performance was better after FPL calibration than after SPL calibration. There was no effect of calibration method on predictions of behavioral threshold.