The Prevalence and Clinical Characteristics of Multidrug-resistant Hospital-acquired Staphylococcus aureus in Medina, Saudi Arabia

Hospital acquired-Staphylococcus aureus (HA-Staphylococcus aureus), particularly methicillin-resistant Staphylococcus aureus (MRSA), are an important source of nosocomial infections with high morbidity and mortality rates. Few reports showed that infections due to HA-Staphylococcus aureus in Saudi Arabia is increasing, particularly infections attributed to HA-MRSA. The study aimed to explore the prevalence and clinical characteristics of HA-Staphylococcus aureus for the first time in Medina, Saudi Arabia. A total of 1262 clinical samples of hospitalized patients were examined for the presence of Staphylococcus aureus through selective culturing on mannitol salt agar. Vitek Compact System and conventional methods were followed to confirm the isolates. Vitek Compact System tested the antimicrobial susceptibility of isolates whereas the standard PCR was employed to detect the genes encoding antimicrobial resistance (mecA and vanA) and virulence factors (tst, et, and LukS-PV). The overall HA-Staphylococcus aureus prevalence was low (6.58%, n = 1262) of which 84.34% (n = 83) were MRSA. Approximately, 57 samples of the 70 MRSA (81.5%) exhibited a multidrug-resistance (MDR) pattern. All the 83 HA-Staphylococcus aureus isolates were negative for the genes encoding toxic shock syndrome toxin, exfoliative toxin, and Panton-Valentine leukocidin. The study was conducted during the Covid-19 pandemic under partial lockdown, restricted hospitalization, and increased disinfection and infection control measures. Therefore, the low prevalence of HA-Staphylococcus aureus should be carefully interpreted and further multicenter investigations could reveal its true incidence in the city. The high prevalence of MDR HA-MRSA is alarming as it highlights inappropriate antibiotic prescriptions to counter staphylococcal infections. HA-Staphylococcus aureus investigated in this study might lack certain virulence factors. However, their MDR traits and invasive nature could worsen the situation if not properly handled

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

First Report of Multi-drug Resistant Staphylococcus haemolyticus in Nosocomial Infections in North Western Saudi Arabia

We report in this study for the first time the prevalence of multiple resistant Staphylococcus haemolyticus in clinical settings in Saudi Arabia. A total of 1060 clinical specimens of hospitalized patients were screened for the presence of S. haemolyticus in the period between September and December 2020. Primary identification of the isolates was carried out by colonial characteristics on mannitol salt agar and clumping factor test, confirmation of presumptive isolates and antimicrobial susceptibility testing was performed by Vitek® 2, while PCR was employed to detect mecA and vanA genes. A total of 20 S. haemolyticus isolates were recovered from 20 samples (blood cultures, urine, nasal swab, wound swab, groin swab, and axilla swab), 90% (P <0.001, x2) of the isolates were multiple resistant to three antimicrobial agents and more. Resistance to oxacillin was exhibited in 95% of the isolates, while none of the isolates were resistant to vancomycin and linezolid, yet resistance to rifampicin was observed in 30 % of the isolates. The findings of this study highlights the emerging trends of Staphylococcus haemolyticus as potential drug resistant pathogen in hospital settings in Saudi Arabia, which requires in depth investigation on molecular understanding on antimicrobial resistance and virulence traits of the strains

COVID-19 Host Genetics Initiative. A first update on mapping the human genetic architecture of COVID-19

The COVID-19 pandemic continues to pose a major public health threat, especially in countries with low vaccination rates. To better understand the biological underpinnings of SARS-CoV-2 infection and COVID-19 severity, we formed the COVID-19 Host Genetics Initiative1. Here we present a genome-wide association study meta-analysis of up to 125,584 cases and over 2.5 million control individuals across 60 studies from 25 countries, adding 11 genome-wide significant loci compared with those previously identified2. Genes at new loci, including SFTPD, MUC5B and ACE2, reveal compelling insights regarding disease susceptibility and severity.</p