Inverse correlation between biofilm production efficiency and antimicrobial resistance in clinical isolates of Pseudomonas aeruginosa.

This study assessed the correlation between biofilm formation in Pseudomonas aeruginosa strains with both the level of antibiotic resistance, and the number of virulence- and biofilm-related genes encoded. A total of sixty-six, non-replicate and prospectively collected P. aeruginosa strains were identified and tested. Potential ampD mutations that may impose resistance to extended-spectrum ß-lactam (ESBL) agents were further explored. Of the sixty-six tested isolates, 40 demonstrated the multidrug resistance (MDR) phenotype, while twenty-six were non-MDR strains. An inverse correlation was observed between antibiotic resistance and the potential capacity to form biofilms. In addition, no correlation was observed between novel ampD mutations and the tendency for MDR isolates to acquire a ß-lactam-resistant phenotype. The present study emphasizes the need for enhanced infection preventive measures in various hospital units, since both MDR and non-MDR P. aeruginosa isolates exhibited a high level of biofilm-forming capacity and the presence of virulence-associated genes.

Pooled Specimen Testing Using Automated Cartridge-Based System for COVID-19: The Cost on Sensitivity.

BACKGROUND: Pooled specimen screening for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can improve laboratory testing capacity. This study assessed the impact of pooling and retesting individual swabs on the overall detection rate and reduction in the frequency of retesting. METHODS: One hundred respiratory swabs specimens were tested individually and in pools of three or five samples using the Cepheid's Xpert® Xpress SARS-CoV-2 test kit. The optimum number of samples per pool was calculated using the application 'A Shiny App for Pooled Testing'. RESULTS: Twenty-five pools were generated from 101 samples. Out of 13 pools that contained five samples each, three pools gave true positive results. While out of the 12 pools that contained three samples each, five pools gave true positive results. Four samples gave a false negative pool result. The overall sensitivity and specificity of the assay in the pools were 66.6% and 100%, respectively. The cycle threshold was reduced in most of the pools compared to individual sample tests. CONCLUSION: The overall pooled test had a remarkable impact on laboratory resources. Yet, caution is warranted when selecting the cases for pooled testing, since the reduction in sensitivity can significantly impact and increase the risk of exposure to infection.

Molecular Surveillance of Multidrug-Resistant Acinetobacter baumannii.

Acinetobacter baumannii, a bacterial strain which demonstrates an elevated wide range multidrug resistance to commonly prescribed antibiotics, has been linked to recent major global outbreaks, raising a major clinical concern. Its reduced antibiotic susceptibility is closely related to the acquisition of a potent carbapenemase and/or intrinsic gene "over expression" through insertion sequences. Hence, this study aimed at investigating the antimicrobial susceptibility and molecular mechanisms underlying ß-lactam resistance in A. baumannii, isolated at an academic medical centre. To understand the basis of resistance, 103 multidrug-resistant (MDR) A. baumannii isolates were collected, their antibiotic susceptibility was tested phenotypically, and then molecular analyses were performed, by testing a range of commonly encountered carbapenemases-OXA-51, OXA-23, NDM, VIM, and KPC. All strains demonstrated pan-resistance to most of the advanced antibiotics tested, including piperacillin/tazobactam, ceftazidime, cefepime, and ciprofloxacin. Moreover, majority of isolates exhibited resistance to imipenem (98.1%) and trimethoprim (90.3%). Approximately 50% of the strains showed meropenem, amikacin, and gentamycin resistance; however, lower resistance rate to tigecycline (4.9%) was noted. Moreover, isolates contained potent carbapenemases such as the intrinsic OXA-51 (89.3%), as well as the acquired resistant genes OXA-23 (68.9%), NDM (84.5%), and VIM (88.3%). The insertion sequence element ISAba1 was only detected in 35.9% of the strains. Potent resistant genes known to be carried on mobile genetic elements that aid the spread of highly resistant phenotypes were observed in a majority of isolates. These findings enforce the need for vigilant infection control measures and continuous surveillance.

The Clinical and Laboratory Impact of Upgrading Clostridioides (formerly Clostridium) difficile Infection Testing from Routine to Molecular Based-Algorithm: an Observational Case-Study from the Eastern Province, Saudi Arabia.

BACKGROUND: Clostridioides (formerly Clostridium) difficile infection (CDI) is linked to misuse of antimicrobials. The prevalence of disease varies with difficulties of establishing the diagnosis because of the lack of sensitivity and specificity of laboratory tests. The clinical impact of upgrading CDI testing from routine to molecular based-algorithm is still unclear. The aim of this study is to assess the impact of upgrading CDI testing from routine to molecular based-algorithm on the management of CDI and evaluate the role of antimicrobials on the course of CDI. METHODS: This is an observational case-study. A total of 564 patients were included from whom stool samples were tested by enzyme immunoassay (EIA) and Xpert for C. difficile. Data on the number and results of tests ordered, antimicrobial exposure, comorbidities, and treatment with metronidazole or vancomycin were collected. The main outcome measures were C. difficile tests (EIA and Xpert C. difficile Assay) and prevalence of CDI. RESULTS: CDI was found in 9 and 10 cases out of 313 and 254 patients tested by the EIA and Xpert C. difficile assay, respectively, giving an overall incidence of 0.03 per 1,000 patient tested. Reduction was noted in the number of tests ordered per patient for presumptive CDI after shifting to the Xpert C. difficile assay which was not statistically significant (p-value 0.2). Also, there was less metronidazole and vancomycin therapy initiated for patients with a negative C. difficile test (p-value 0.2) observed with molecular testing. CONCLUSIONS: Xpert C. difficile testing is a supportive tool for diagnosing CDI with rapid turnaround time that is helpful for patient management and initiating effective infection control measures. The clinical accuracy of the assay is still to be determined in the context of low carriage rate in the local patient population.

Comparative and molecular analysis of MRSA isolates from infection sites and carrier colonization sites.

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) constitutes a major global health concern causing hospital and community acquired infections. A wide diversity of MRSA genotypes are circulating in geographically related regions. Therefore understanding the molecular epidemiology of MRSA is fundamental to design control and clearance measures. METHODS: A total of 106 MRSA isolates from infection (51) and carrier colonization sites (55) are characterized genetically based on SCCmec and MLST genotyping methods in addition to detection of PVL, TSST-1 and enterotoxins. RESULTS: Sccmec-IV was the most frequently detected genotype (77.3%) followed by genotype V (13.2%) and III (9.4%). SCCmec-IVa was more prevalent among the carrier group (p value 0.002). CC80 was the most commonly identified clonal complex (CC). CC6 and CC22 were significantly more prevalent among the carrier group (p value 0.02 and 0.01, respectively). PVL was highly prevalent among the isolates (58.5%). PVL was detected in 70.6% of isolates from infection sites and 47.3% of isolates from carriers. All strains were sensitive to vancomycin, however, MRSA strains isolated from infection sites had significantly higher MICs compared to strains isolated from carrier colonization sites (p value 0.021). Five new sequence types mainly from the carrier group were identified and described in the study. CONCLUSIONS: MRSA population is genetically very diverse among carriers and infected individuals. With SCCmec type IV being most prevalent, this suggests a community origin of most MRSA strains. Therefore very well designed surveillance and clearance strategies should be prepared to prevent emergence and control spread of MRSA in the community.

Carbapenem resistance in Enterobacterales: Predicting clinical outcomes in bloodstream infections.

PURPOSE: Carbapenem-resistant Enterobacterales (CRE) are a global concern due to their high mortality rates and limited therapeutics. CRE-caused bloodstream infections (BSIs) are challenging to manage, especially in healthcare settings. This study aimed to investigate the predictors of mortality in BSI patients caused by CRE. METHODS: A single center prospective study to examine the characteristics of BSI caused by CRE in a large academic hospital over 15 months. The main outcomes were microbiological characteristics and clinical outcomes of patients at 28 days based on a step-wise regression analysis. RESULTS: A total of 76 episodes of BSI due to CRE were included. The study found that the most common type of carbapenemase was OXA-48 (69.7 %, n = 53), followed by the co-existence of OXA-48 and MBL (26.3 %, n = 20), with Klebsiella pneumoniae being the most common (90 %, n = 69). Patients with OXA-48-BSI were more likely to have a urinary source of infection, while patients with MBL-BSI were more likely to have a non-urinary source of infection. All cases (100 %) had medical devices. Around 30.3 % of patients received effective empirical treatment, while 61.8 % received adequate therapy at 48 h. The overall mortality rate was 42.1 % (n = 32), and the main predictors of mortality in this study were the presence of sepsis and inadequate initial therapy, while age >65 predicted mortality in the linear regression but not the stepwise regression model. CONCLUSION: CRE-BSIs are a serious health threat. The study highlights the need for preventive strategies focused on high-risk patients and proper device management to reduce BSI.

Clinical and epidemiological characteristics of multi-drug resistant Enterobacterales isolated from King Fahad Hospital of the University, AlKhobar, Saudi Arabia.

Multi-drug resistant (MDR) Enterobacterales remain a major clinical problem. Infections caused by carbapenem-resistant strains are particularly difficult to treat. This study aimed to assess the clinical and epidemiological characteristics of MDR Enterobacterales isolates. A total of 154 non-repetitive clinical isolates, including Escherichia coli (n = 66), Klebsiella pneumoniae (n = 70), and other Enterobacterales (n = 18), were collected from the Diagnostic Microbiology Laboratory at King Fahad Hospital of the University. Most E. coli isolates were collected from urine specimens (n = 50, 75.8%) and resistance against the third and fourth-generation cephalosporins (ceftriaxone, ceftazidime, cefixime, and cefepime) and fluoroquinolones (ciprofloxacin and levofloxacin) was assessed. Clonal relatedness analysis using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) revealed two clones (E. coli A and B), each comprising two strains. Most K. pneumoniae samples were collected from respiratory specimens (27.1%, 20 samples), and the strains showed overall resistance to most of the antimicrobials tested (54%‒100%). Moreover, clonal-relatedness analysis using ERIC-PCR revealed seven major clones of K. pneumoniae. These findings suggest nosocomial transmission among some identical strains and emphasize the importance of strict compliance with infection prevention and control policies and regulations. Environmental reservoirs could facilitate this indirect transmission, which needs to be investigated.

Antimicrobial Resistance in Ventilator-Associated Pneumonia: Predictive Microbiology and Evidence-Based Therapy.

Ventilator-associated pneumonia (VAP) is a serious intensive care unit (ICU)-related infection in mechanically ventilated patients that is frequent, as more than half of antibiotics prescriptions in ICU are due to VAP. Various risk factors and diagnostic criteria for VAP have been referred to in different settings. The estimated attributable mortality of VAP can go up to 50%, which is higher in cases of antimicrobial-resistant VAP. When the diagnosis of pneumonia in a mechanically ventilated patient is made, initiation of effective antimicrobial therapy must be prompt. Microbiological diagnosis of VAP is required to optimize timely therapy since effective early treatment is fundamental for better outcomes, with controversy continuing regarding optimal sampling and testing. Understanding the role of antimicrobial resistance in the context of VAP is crucial in the era of continuously evolving antimicrobial-resistant clones that represent an urgent threat to global health. This review is focused on the risk factors for antimicrobial resistance in adult VAP and its novel microbiological tools. It aims to summarize the current evidence-based knowledge about the mechanisms of resistance in VAP caused by multidrug-resistant bacteria in clinical settings with focus on Gram-negative pathogens. It highlights the evidence-based antimicrobial management and prevention of drug-resistant VAP. It also addresses emerging concepts related to predictive microbiology in VAP and sheds lights on VAP in the context of coronavirus disease 2019 (COVID-19).

Bloodstream Infections Caused by Drug Resistant Ralstonia species: A Case Series During the COVID-19 Pandemic.

Ralstonia spp. is an emerging, non-fermentative Gram-negative rod that demonstrates multidrug resistance. Herein, four cases of bloodstream infections (BSI) caused by R. mannitolilytica or R. pickettii are presented. All the cases had comorbidities that predisposed them to this opportunistic infection. The microbiological assessment showed carbapenemase genes carried out in two strains with minimal inhibitory concentrations > 32 µg/mL to imipenem and meropenem. Fluoroquinolones and trimethoprim-sulphamethoxazole were the most potent agents showing activity against 3/4 strains (75%), although treatment should be susceptibility-dependent for each strain. This case series highlights the possibility of co-infection by a rare organism during the COVID-19 pandemic and the importance of the readiness of diagnostic laboratories to support the diagnosis of uncommon pathogens.

Clinical and Microbiological Characteristics of Candidemia Cases in Saudi Arabia.

Purpose: Candidemia and antifungal resistance are major healthcare challenges. The aim of this study is to describe the frequency of candidemia cases, distribution of Candida spp., and the associated risk factors for mortality in an academic institution in Saudi Arabia over an 18-month period. We also evaluated the susceptibility patterns of Candida blood isolates. Methods: Candidemia cases were collected from King Fahad Hospital of the University over the period between July 1st, 2020 through December 31st, 2021. They were prospectively reviewed for the preceding risk factors and antifungal (AF) susceptibility, testing results to fluconazole (FL), voriconazole (VO), itraconazole (IT), posaconazole (PO), caspofungin (CASP), anidulafungin (AND), micafungin (MYC), flucytosine (FLC) and amphotericin B (AMPB) using a broth microdilution kit (Sensititre™ YeastOne). Results: A total of 48 candidemia isolates were included that were isolated from 43 patients. The median age of cases was 62 ± 23.3 years (60.4% males and 83% ICU patients). Independent risk factors for mortality at 30 days in candidemia patients were age, COVID-19 co-infection, and use of tocilizumab. The most commonly isolated species were C. glabrata and C. parapsilosis (22.9% each) followed by C. albicans (18.75%). AF resistance for ≥1 antifungal was detected in 39.3% of 33 cases tested, with no cross-resistance identified. Resistance rates for each AF were as follows: FL (18%), VO (6%), IT (6%), PO (9%) and AMPB (3%). No resistance was seen for echinocandins apart from one C. krusei strain showing an intermediate result for CASP. Conclusion: The study showed an overall high rate of non-albicans Candida, with the predominance of C. parapsilosis and C. glabrata, representing a therapeutic challenge. AF resistance rate was high which emphasizes the importance of continuing surveillance and providing accurate and reliable tools in the laboratories for rapid speciation and susceptibility testing.

Microbiological trends and mortality risk factors of central line-associated bloodstream infections in an academic medical center 2015-2020.

BACKGROUND: Despite tremendous efforts to prevent central line-associated bloodstream infections, they still remain life-threatening complications among hospitalized patients with significant morbidity and mortality worldwide. The emerging antibiotic-resistant bacteria and other risk factors, including patient comorbidities, complicate patient management. METHODS: A single-center retrospective observational study was conducted at King Fahad Hospital of the University, Eastern Province, Saudi Arabia. Hospitalized patients with confirmed central line-associated bloodstream infections between January 2015 and December 2020 were included. The primary objectives were to investigate the trends in antibiotic susceptibility patterns of the causative agents, coexisting comorbid conditions, and other risk factors associated with mortality. RESULTS: A total of 214 patients with confirmed central line-associated bloodstream infections were included (CLABSI). The overall 30-day mortality rate was 33.6%. The infection rates per 1000 central line days for medical, surgical, and pediatric intensive care units were 4.97, 2.99, and 4.56 per 1000 CL days, respectively. The overall microbiological trends showed a predominance of Gram-negative agents, a steady increase of fungal CLABSI up to 24.0% in 2020, and a high prevalence of multidrug resistance up to 47% of bacterial CLABSI. In addition, the study indicates a significant negative surviving correlation with diabetes mellitus, cardiovascular disease, lung disease, chronic kidney disease, and the presence of ≥ 3 comorbidities (P < 0.05). CONCLUSION: The microbiological trends of the study population demonstrated a steady increase of CLABSI caused by Candida spp. with a predominance of Gram-negative pathogens. Stratifying the patients according to relevant mortality risk factors, including patient comorbidities, will help reduce CLABSI rates and improve patient outcomes.

Diagnosis of group A streptococcal pharyngitis in the paediatric emergency department using a fluorescence-based RADT: predicted impact on antibiotic prescription.

Introduction. Using rapid antigen diagnostic tests (RADTs) in clinical practice has shown excellent specificity but often has diminished sensitivity.Gap Statement. Local data for evaluating the diagnostic performance of a new fluorescence-based RADT and its influence on the antibiotic prescription rate are not available.Aim. To evaluate the accuracy of fluorescent immunoassay (FIA)-RADTs for diagnosing group A streptococcal (GAS) pharyngitis among children and its estimated effect as a point of care test (POCT) on the antibiotic prescription rate at the paediatric emergency department.Methodology. A prospective study was conducted, comprising children 3 to 14 years old presenting with pharyngitis. Throat swab culture and FIA-RADTs were performed on all samples. Conventional PCR was performed on the discordant samples.Results. A total of 246 children were included in this study. The sensitivity, specificity, and positive and negative predictive values of the FIA-RADT, based on culture results and PCR detection combined, were 95.6, 96.8, 94.6 and 97.4 %, respectively. Antibiotics have been prescribed to 162 (65.9 %) children; however, if FIA-RADTs had been added in the clinical practice as a POCT, only 92 (37.4 %) children would have received antibiotics in total. Additionally, implementation of FIA-RADTs would significantly reduce the antibiotic prescription rate from 48.8 and 60.6 % to 9.5 and 31.9 % among patients with clinical scores of 2 and 3, respectively.Conclusion. The new FIA-RADT is simple, prompt and reliable. It is helpful in clinical settings and may be used to reduce antibiotic overprescription, especially for children who have a low risk for GAS pharyngitis, according to the clinical score.

Synthesis and biological evaluation of purpurealidin E-derived marine sponge metabolites: aplysamine-2, aplyzanzine A, and suberedamines A and B.

Five purpurealidin-derived marine secondary sponge metabolies have been synthesized through the carbodiimide coupling of an appropriate bromotyrosine unit. The structure elucidations have been confirmed through direct comparison with spectroscopic data of isolated natural products. Aplyzanzine A has been shown to be the most active product against a broad bacterial and fungal screen, demonstrating MIC values 2 to 4 times lower than the other metabolites in this study. Compounds 2, 3, 4a, and 5-7 exhibit a modest inhibition against slow growing mycobacteria (MIC 25-50 µg/mL), including Mycobacterium tuberculosis. iso-Anomoian A and suberedamine B showed antitumor activity in the NCI-DTP60 cell line screen at single-digit micromolar concentrations, with iso-anomoian A inhibiting 53 cell lines. These molecules present novel scaffolds for further optimization.

Pneumococcal empyema: Resistance patterns, fitness cost and serotype distribution.

BACKGROUND: Streptococcus pneumoniae is a recognized etiology of invasive infections including parapneumonic empyema, and its resistance to antibiotics is evolving worldwide, raising concerns of encountering untreatable strains. This study measured the serotype distribution, antimicrobial susceptibility and biological cost incurred by resistance of pneumococci from pleural samples. METHODS: The serotype profiles, susceptibility results and growth rates were phenotypically determined for a panel of clinical strains of S. pneumoniae from cases of empyema between 2011 and 2019. RESULTS: Of 24 empyema cases, the isolated strains belonged to seven serotypes in the following descending order; 19A, 11A/D, 19F, 3, 7F, 1/6B while two strains remained non-typable. Penicillin susceptibility was shown in <80% of the isolates, while parenteral cephalosporins (cefuroxime and ceftriaxone) demonstrated activity in 83.3 and 95.8% respectively. High resistance frequency was noted for macrolides and sulfonamides, but the strains were uniformly sensitive to respiratory fluroquinolones, vancomycin and linezolid. The macrolide-resistant strain exhibited a high growth rate, suggesting a possible beneficial effect. Phenotypes with mono-resistance to sulfonamides and clindamycin were equally fit as the susceptible counterpart strains. Resistance to multiple antimicrobial agents resulted in a high degree of fitness deficit, while other resistant phenotypes were less fit. CONCLUSIONS: The pneumococcal conjugate vaccine PCV13 serotypes still circulate in the community. The data indicate that resistance to certain antimicrobials incurs an apparent fitness cost in pneumococci which may limit the dissemination of such strains while low fitness cost, seen in case of resistance to macrolides, may contribute to the spread of resistant clones.

Eleven-Year surveillance of methicillin-resistant Staphylococcus aureus infections at an Academic Health Centre.

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen associated with nosocomial and community infections. There is a continual focus on the epidemiology of this public health threat owing to the increase in its spread and rapid development of resistance. Aim: We aimed to demonstrate the time trend of antibiotic resistance by describing the epidemiology of MRSA infections at an academic health centre. Methodology: We retrospectively reviewed cases during an 11-year period (from January 2009 to December 2019) with positive cultures for MRSA from various clinical sites in King Fahad Hospital of the University, to understand their clinical and microbiological profiles. Screening and colonisation samples were excluded. Results: A total of 1338 MRSA isolates were identified, with an increasing trend from 5.2% to 14.5% during 2009-2019. Skin and soft tissue samples were the most common source (52.4%) of MRSA infections. Vancomycin activity remained stable against MRSA, and only one isolate showed resistance to linezolid (< 1%). A significant reduction in susceptibility to clindamycin (p = 0.003), trimethoprim-sulfamethoxazole (p = 0.001), and rifampin (p < 0.0001) was detected over the study period. Conclusions: MRSA infections still represent a significant burden on healthcare systems. Our data support the need for constant local and regional surveillance to devise relevant protocols to manage MRSA infections. Empirical therapy needs to consider the changing antimicrobial susceptibility trends among MRSA isolates.

Nano-treatment of HEPA filters in COVID-19 isolation rooms in an academic medical center in Saudi Arabia.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has spread globally. The major reservoir for SARS-CoV-2 transmission remains controversial, with the airborne route remaining a possible transmission vehicle for carrying the virus within indoor environments. This study aimed to detect contamination of SARS-CoV-2 in high-efficiency particulate air (HEPA) filters within hospital isolation rooms of confirmed COVID-19 patients, exploring the role of nano-treatment of these filters with silver and titanium dioxide nanoparticles (Ag/TiO2 NPs). MATERIALS AND METHODS: We investigated the effectiveness of Ag-NPs/TiO2-treated HEPA filters in the air of rooms occupied by patients with confirmed COVID-19 in a university teaching hospital in the Eastern province of Saudi Arabia during the first wave of the pandemic. Ag/TiO2 NPs were designed and coated on HEPA filters to examine the filtration efficiency and antiviral ability in the presence of aerosolized virus particles. A total of 20 viral swab samples were collected from five patients' rooms before and after treatment with nanoparticle-prepared solutions into the sterile virus-transporting media. Samples were evaluated for SARS-CoV-2 with a reverse transcription-polymerase chain reaction. RESULTS: Two samples taken from the HEPA filter air exhaust outlets prior to nano-treatment tested positive for SARS-CoV-2 RNA in the intensive care unit, which has stringent aerosolization control procedures, suggesting that small virus-laden droplets may be displaced by airflow. All air samples collected from the HEPA filters from the rooms of patients with confirmed COVID-19 following nano-treatment were negative. CONCLUSION: We recommend further experimental exploration using a larger number of HEPA filters in areas with aerosol-generating procedures, along with viability studies on the HEPA filters to facilitate decision-making in high-risk facilities regarding the replacement, storage, and disposal of HEPA filters in wards occupied by cases diagnosed with a highly transmissible disease.

Bacterial and Fungal Coinfection in Critically Ill COVID-19 Cases and Predictive Role of Procalcitonin During the First Wave at an Academic Health Center.

BACKGROUND: Coinfection at various sites can complicate the clinical course of coronavirus disease of 2019 (COVID-19) patients leading to worse prognosis and increased mortality. We aimed to investigate the occurrence of coinfection in critically ill COVID-19 cases, and the predictive role of routinely tested biomarkers on admission for mortality. METHODS: This is a retrospective study of all SARS-CoV-2-infected cases, who were admitted to King Fahad Hospital of the University between March 2020 and December 2020. We reviewed the data in the electronic charts in the healthcare information management system including initial presentation, clinical course, radiological and laboratory findings and reported all significant microbiological cultures that indicated antimicrobial therapy. The mortality data were reviewed for severely ill patients who were admitted to critical care units. RESULTS: Of 1091 admitted patients, there were 70 fatalities (6.4%). 182 COVID-19 persons were admitted to the critical care service, of whom 114 patients (62.6%) survived. The in-hospital mortality was 13.4%. Coinfection was noted in 67/68 non-survivors, and Gram-negative pathogens (Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumanni) represented more than 50% of the etiological agents. We noted that the serum procalcitonin on admission was higher for non-survivors (Median = 1.6 ng/mL ± 4.7) than in survivors (Median = 0.2 ng/mL ± 4.2) (p ≤ 0.05). CONCLUSION: Coinfection is a serious complication for COVID-19 especially in the presence of co-morbidities. High levels of procalcitonin on admission may predict non-survival in critically ill cases in whom bacterial or fungal co-infection is likely.

Low levels of soluble DPP4 among Saudis may have constituted a risk factor for MERS endemicity.

Most of the cases of Middle East respiratory syndrome coronavirus (MERS-CoV) were reported in Saudi Arabia. Dipeptidyl peptidase-4 (DPP4) was identified as the receptor for the virus. The level of soluble DPP4 (sDPP4) was found to be reduced in MERS-CoV infected patients while high levels of sDPP4 were suggested to be protective against MERS-CoV in animal models. We investigated whether the Saudi population has lower levels of sDPP4 which makes them more susceptible to MERS-CoV infection and, therefore, could explain the larger number of cases from the country. Blood samples were collected from 219 Saudi blood donors and 200 blood donors from other ethnic groups. The plasma level of sDPP4 was measured by ELISA and the following SNPs in the DPP4 gene; rs35128070, rs1861978, rs79700168, and rs17574, were genotyped by TaqMan SNP genotyping assay. The average level of plasma sDDP4 was significantly lower in Saudis than other Arabs and non-Arabs (P value 0.0003 and 0.012, respectively). The genotypes AG of rs35128070 and GT of rs1861978 were significantly associated with lower sDPP4 among Saudis (P value 0.002 for each). While both genotypes AA and AG of rs79700168 and rs17574 were associated with significantly lower average sDPP4 level in Saudis compared to other ethnic groups (P value 0.031 and 0.032, and 0.027 and 0.014, respectively). Herein, we report that the Saudi population has lower levels of plasma sDPP4 than other ethnic groups, which is associated with genetic variants in the DPP4 gene. This may have contributed to increase the susceptibility of the Saudi population to MERS-CoV infection and could be a factor in the long-lasting persistence of the virus in the country.

Predictive Role of Targeted, Active Surveillance Cultures for Detection of Methicillin-Resistant Staphylococcus aureus.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) colonisation is an important source of healthcare-acquired infections. Reliable screening strategies for MRSA colonisation are essential for the timely implementation of infection control measures. AIM: This study determined reliable MRSA screening sites to predict colonisation in resource-limited settings and estimated the impact of missed MRSA cases when shifting from multi- to single-site screening. METHODOLOGY: A cross-sectional study was conducted in patients with positive MRSA surveillance cultures from the routinely screened sites (nasal, axillary, groin, and throat) from January 2009 to December 2019. RESULTS: A total of 1906 screening tests were positive for MRSA cultures (n = 1345 patients). As a single site, the nasal cavity showed the highest MRSA detection, with a sensitivity of 66.8% (95% CI = 64-69) with 277.9 missed isolation days. Screening three or more anatomical sites detected 97-100% of MRSA cases, with 0-24.5 missed isolation days. Screening the axilla and groin separately or in combination showed a good clinical utility index (CUI) of >0.6 to <0.8, while an excellent CUI was obtained upon screening other site samples (>0.8). The combined nasal and throat cultures demonstrated a sensitivity of 93.2 (95% CI = 91-94) with 57.2 missed isolation days. CONCLUSION: Multi-site screening is the optimal strategy for minimising MRSA exposure within a healthcare facility. For active MRSA surveillance, a combination of nasal and throat cultures can provide a practical approach in low-resource settings compared to nasal sampling alone.

The Environmental Deposition of Severe Acute Respiratory Syndrome Coronavirus 2 in Nosocomial Settings: Role of the Aerosolized Hydrogen Peroxide.

BACKGROUND: Data on the role of aerosolized hydrogen peroxide (AHP) systems in the control of the COVID-19 pandemic are still emerging. This study provides evidence of the environmental shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the hospital environment, and the efficacy of AHP to eliminate it. METHODS: A total of 324 environmental sites (224 surfaces and 100 air samples) belonging to 54 patient rooms were contextually collected and tested for genes of SARS-CoV-2 using RT-PCR assays and Xpert® Xpress SARS-CoV-2. RESULTS: The SARS-CoV-2 viral genome was detected in seven sites (2.5%) of three patients' rooms, including six highly touched surfaces and one air sample. Viral shedding was directly related to the distance from the patient, with 1, 1.9, and 3.5% of samples testing positive at 3, 2, and 1 meter, respectively (P-value=0.02). None of the sites showed the viral genome following application of 6% AHP. Of note, the viral genome was detected at 2 meters of a mildly symptomatic case on a face mask in the absence of aerosol generating procedures. CONCLUSION: Our data support the possible role of the hospital environment as a source of infection, and the efficacy of AHP to eliminate the virus. Further studies are needed to address the viability of the pathogen in these nosocomial sites and the cost-effectiveness of routine hospital disinfection procedures using AHP for SARS-CoV-2.