The prevalence of patients admitted to intensive care units (ICUs) with SARS-CoV-2 infection who were prescribed antibiotics is undetermined and might contribute to the increased global antibiotic resistance. This systematic review evaluates the prevalence of antibiotic prescribing in patients admitted to ICUs with SARS-CoV-2 infection using PRISMA guidelines. We searched and scrutinized results from PubMed and ScienceDirect databases for published literature restricted to the English language up to 11 May 2021. In addition, we included observational studies of humans with laboratory-confirmed SARS-CoV-2 infection, clinical characteristics, and antibiotics prescribed for ICU patients with SARS-CoV-2 infections. A total of 361 studies were identified, but only 38 were included in the final analysis. Antibiotic prescribing data were available from 2715 patients, of which prevalence of 71% was reported in old age patients with a mean age of 62.7 years. From the reported studies, third generation cephalosporin had the highest frequency amongst reviewed studies (36.8%) followed by azithromycin (34.2%). The estimated bacterial infection in 12 reported studies was 30.8% produced by 15 different bacterial species, and S. aureus recorded the highest bacterial infection (75%). The fundamental outcomes were the prevalence of ICU COVID-19 patients prescribed antibiotics stratified by age, type of antibiotics prescribed, and the presence of co-infections and comorbidities. In conclusion, more than half of ICU patients with SARS-CoV-2 infection received antibiotics, and prescribing is significantly higher than the estimated frequency of identified bacterial co-infection.

Ultrasonography is the most widely used imaging technique in cardiovascular medicine. In this technique, a piezoelectric crystal produces, sends, and receives high frequency ultrasound waves to the body to create an image of internal organs. It enables practical real time visualization in a non-invasive manner, making the modality especially useful to image dynamic cardiac structures. In the last few decades, echocardiography has been applied to in vivo cardiac disease models, mainly to rodents. While clinical echocardiography platforms can be used for relatively large animals such as pigs and rats, specialized systems are needed for smaller species. Theoretically, as the size of the imaged sample decreases, the frequency of the ultrasound transducer needed to image the sample increases. There are multiple modes of echocardiography imaging. In Doppler mode, erythrocytes blood flow velocities are measured from the frequency shift of the sent ultrasound waves compared to received echoes. Recorded data are then used to calculate cardiac function parameters such as cardiac output, as well as the hemodynamic shear stress levels in the heart and blood vessels. The multi-mode (i.e., b-mode, m-mode, Pulsed Doppler, Tissue Doppler, etc.) small animal ultrasound systems in the market can be used for most in vivo cardiac disease models including mice, embryonic chick and zebrafish. These systems are also associated with significant costs. Alternatively, there are more economical single-mode echocardiography platforms. However, these are originally built for mice studies and they need to be tested and evaluated for smaller experimental models. We recently adapted a mice Doppler echocardiography system to measure cardiac flow velocities for adult zebrafish and embryonic chicken. We successfully assessed cardiac function and hemodynamic shear stress for normal as well as for diseased embryonic chicken and zebrafish. In this paper, we will present our detailed protocols for Doppler flow measurements and further cardiac function analysis on these models using the setup. The protocols will involve detailed steps for animal stabilization, probe orientation for specific measurements, data acquisition, and data analysis. We believe this information will help cardiac researchers to establish similar echocardiography platforms in their labs in a practical and economical manner.

Gold nanorods (AuNRs) were synthesized by the seed-mediated wet chemical method using a binary surfactant system. AuNRs were stabilized with polyethylene glycol, then functionalized with 4-mercaptophenol (4-MPH) ligand by surface ligand exchange. The surface-functionalized AuNRs (4-MPH-AuNRs) exhibited a typical UV–vis spectrum of AuNRs with a slightly shifted longitudinal peak. Furthermore, 4-MPH-AuNRs demonstrated a similar Fourier-Transformed Infrared spectrum to 4-MPH and a fading of the thiol band, which suggests a successful functionalization through thiol-gold binding. The antibacterial and antibiofilm activities of 4-MPH-AuNRs were evaluated against a clinical isolate of Methicillin-Resistant Staphylococcus aureus (MRSA). The results indicate that 4-MPH-AuNRs exhibit a bactericidal activity with a minimum inhibitory concentration (MIC) of ~ 6.25 $$\upmu$$ μ g/mL against a planktonic suspension of MRSA. Furthermore, 4-MPH-AuNRs resulted in a 1.8–2.9 log-cycle reduction of MRSA biofilm viable count over a concentration range of 100–6.0 $$\upmu$$ μ g/mL. The bacterial uptake of the surface-modified nanorods was investigated by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM) imaging; the results reveal that the nanorods were internalized into the bacterial cells after 6 h (h) of exposure. SEM imaging revealed a significant accumulation of the nanorods at the bacterial cell wall and a possible cellular internalization. Thus, 4-MPH-AuNRs can be considered a potential antibacterial agent, particularly against MRSA strain biofilms.

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Airborne bacteria pose a potential risk to human health upon inhalation in the indoor environments of health care facilities. Airborne bacteria may originate from various sources, including patients, workers, and daily visitors. Hence, this study investigates the quantity, size, and identification of airborne bacteria indoors and outdoors of four Primary Health Care Centers (PHCC) in Doha, Qatar. Air samples were collected from the lobby, triage room, and outside environment of the centers, including, Qatar University (QU-HC), Al-Rayyan (AR-HC), Umm-Ghuwailina (UG-HC), and Old Airport (OA-HC) between August 2020 and March 2021, throughout both the hot and the cold seasons. Samples were collected using an Anderson six-stage cascade impactor. The mean of the total colony-forming units was calculated per cubic meter of air (CFU/m3). QU-HC had the lowest mean of total bacterial count compared with other centers in the indoor and outdoor areas with 100.4 and 99.6 CFU/m3, respectively. In contrast, AR-HC had the highest level, with 459 CFU/m3 indoors, while OA-HC recorded the highest bacterial concentration of the outdoor areas with a total mean 377 CFU/m3. In addition, 16S rRNA sequencing was performed for genera identification. Staphylococcus, Acinetobacter, Bacillus, and Pseudomonas were the four most frequently identified bacterial genera in this study. The abundance of airborne bacteria in the four health centers was higher in the cold season. About 46% of the total airborne bacterial count for three PHCC centers exceeded 300 CFU/m3, making them uncompliant with the World Health Organization’s (WHO) recommendation for indoor settings. Consequently, an IAQ standards should be shaped to establish a baseline for measuring air pollution in Qatar. Additionally, it is crucial to understand seasonal fluctuations better so that hospitals can avoid rising and spreading infection peaks.