Microbial surveillance of Hajj tents: Bioaerosol sampling coupled with real-time multiplex PCR.

BACKGROUND: Respiratory tract infections are common among pilgrims attending annual Hajj in Mecca, Saudi Arabia. Pilgrims typically spend most of the Hajj period inside ventilated tents, where microorganisms may be transmitted through bioaerosols and droplets. OBJECTIVE: To perform microorganism surveillance inside Hajj tents and assess the similarities between microorganisms isolated from tent bioaerosol samples and nasopharyngeal swabs (NP) of tent occupants. METHODS: Respiratory microorganisms in bioaerosols collected from Hajj tents over a 4-day period were compared with NP of tent occupants using real-time multiplex polymerase chain reaction analysis. RESULTS: A total of 152 samples were collected: 120 tent bioaerosol samples collected on days 9, 10, 11, and 12 of Dhu al-Hijjah, and 32 NP collected on day 12 of Dhu al-Hijjah (corresponding to 23/08/2018). Eighty-three (69.2%) bioaerosol samples tested positive for at least 1 microorganism, with the number of pathogens increasing over the 4 days of sampling. Twenty-seven (84.38%) NP swabs from tent occupants also tested positive. Microorganisms identified in pilgrim nasal carriage and tent bioaerosol samples were similar, and included K. pneumonia, S. aureus, S. pneumonia, human adenovirus, Moraxella, influenza A, and H. influenza. CONCLUSIONS: The data suggest that the Hajj tent environment may contribute to the spread of airborne infections during Hajj. This can have important ramifications for novel pathogens with pandemic potential.

The Effect of Short Treatment with Nigella Sativa on Symptoms, the Cluster of Differentiation (CD) Profile, and Inflammatory Markers in Mild COVID-19 Patients: A Randomized, Double-Blind Controlled Trial.

The current study investigated the impact of different doses of Nigella sativa seeds on the symptoms, the cluster of differentiation profile group, and inflammatory markers of mild COVID-19 cases. METHODS: The study was a double-blind placebo-controlled clinical trial. Patients with mild and asymptomatic SARS-CoV-2 infection patients were randomly subdivided into seven subgroups: Group (GP) 1: received charcoal capsules as a control group, and GP 2: received three capsules of whole Nigella sativa seeds daily, two capsules in the morning and one in the evening; GP 3: received three capsules of whole Nigella sativa seeds every 12 h, GP 4: received five capsules in the morning and four capsules of whole Nigella sativa seeds in the evening, GP 5: received one capsule of Nigella sativa powder every 12 h; GP 6: received two capsules of Nigella sativa powder every 12 h; GP 7: received three capsules of Nigella sativa powder every 12 h; all treatment course was for ten days. Inflammatory parameters were assessed before and after interventions. RESULTS: 262 subjects were included in the final analysis. No significant difference was detected regarding age, gender, and nationality. No significant differences were detected between the inflammatory marker in all groups. The WBCs showed a significant difference between before and after the intervention. While for procalcitonin, a significant difference was demonstrated in groups 1,4, and 6. CONCLUSIONS: The current randomized clinical trial did not reveal a significant effect of ten days of treatment with various doses of Nigella sativa on symptoms, differentiation profile, and inflammatory markers of patients with COVID-19. As a natural product, the effect of Nigella sativa on disease requires weeks to manifest itself.

The diagnostic impact of implementing a molecular-based algorithm to standard mycobacterial screening at a reference laboratory with an intermediate prevalence for non-respiratory samples.

Rapid, reliable results can be given by molecular, direct detection and identification of the Mycobacterium tuberculosis (MTB/Mtb) complex from clinical samples. The Xpert MTB/RIF assay is an assay that has been availablefor more than a decade for identification of Mycobacterium tuberculosis and resistance to rifampicin. However, there is minimal evidence on its clinical usefulness in paucibacillary, non-respiratory samples. The Xpert MTB/RIF assay clinical utility index, its diagnostic characteristics and the number required to diagnose 2935 non-respiratory specimens submitted for routine mycobacterial work-up in a reference laboratory in an intermediate prevalence setting per specimen form were evaluated. The Xpert MTB/RIF assay showed a variable clinical utility index and number required to diagnose (NND) depending on the type of specimen, which was moderate in tissue biopsies (NND = 1.8) and excellent in pus and urine samples, compared to acid-fast microscopy and culture as a gold standard technique (NND = 1.1 and 1.2). Microscopy, on the other hand, consistently showed a weak to fair index of clinical usefulness in all specimen forms, with in NND of 2.3-12.5. The NND for detecting tuberculous infection in the cerebrospinal fluid by the Xpert MTB/RIF assay was noted to be 1.2, with a moderate clinical utility index of 0.8. The evidence presented indicates that the overall appropriate diagnostic utility of the Xpert MTB/RIF assay is clinically successful in most non-respiratory samples. To check the cost-effectiveness and prognostic effect of integrating this completely automated molecular-based assay into the routine testing algorithm for non-respiratory mycobacterial specimens, further data must be collected.

MERS-CoV infection is associated with downregulation of genes encoding Th1 and Th2 cytokines/chemokines and elevated inflammatory innate immune response in the lower respiratory tract.

MERS-CoV, a highly pathogenic virus in humans, is associated with high morbidity and case fatality. Inflammatory responses have a significant impact on MERS-CoV pathogenesis and disease outcome. However, CD4+ T-cell induced immune responses during acute MERS-CoV infection are barely detectable, with potent inhibition of effector T cells and downregulation of antigen presentation. The local pulmonary immune response, particularly the Th1 and Th2-related immune response during acute severe MERS-CoV infection is not fully understood. In this study, we offer the first insights into the pulmonary gene expression profile of Th1 and Th2-related cytokines/chemokines (Th1 & Th2 responses) during acute MERS-CoV infection using RT2 Profiler PCR Arrays. We also quantified the expression level of primary inflammatory cytokines/chemokines. Our results showed a downregulation of Th2, inadequate (partial) Th1 immune response and high expression levels of inflammatory cytokines IL-1α and IL-1ß and the neutrophil chemoattractant chemokine IL-8 (CXCL8) in the lower respiratory tract of MERS-CoV infected patients. Moreover, we identified a high viral load in all included patients. We also observed a correlation between inflammatory cytokines, Th1, and Th2 downregulation and the case fatality rate. Th1 and Th2 response downregulation, high expression of inflammatory cytokines, and high viral load may contribute to lung inflammation, severe infection, the evolution of pneumonia and ARDS, and a higher case fatality rate. Further study of the molecular mechanisms underlying the Th1 and Th2 regulatory pathways will be vital for active vaccine development and the identification of novel therapeutic strategies.

Detection of clostridium difficile antigen and toxin in stool specimens: Comparison of the C. difficile quik chek complete enzyme immunoassay and GeneXpert C. difficile polymerase chain reaction assay.

BACKGROUND/AIMS: Accurate and rapid laboratory diagnosis of Clostridium difficile infections (CDI) remains a significant challenge. A two-step algorithm for detection of toxigenic C. difficile in stool based on initial screening for glutamate dehydrogenase assay followed by confirmation by toxin A+B detection using an enzyme immunoassay (EIA) or molecular assay has been proposed. We aimed to evaluate the C. difficile Quik Chek Complete® (QCC-EIA) versus the GeneXpert® C. difficile polymerase chain reaction (PCR) assay in this two-step algorithm. MATERIALS AND METHODS: Two hundred and ten liquid stool samples obtained between June 2014 and June 2015 from patients suspected of CDI were tested by the QCC-EIA and GeneXpert PCR assay. The GeneXpert assay was used as the reference standard to calculate the QCC-EIA sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: Of the 210 stool samples tested, 43 (20.5%) were positive by QCC-EIA, while 31 (14.8%) were positive by GeneXpert assay. The sensitivity and specificity of the QCC-EIA were found to be 100 and 93%, respectively; the PPV and NPV were 72 and 100%, respectively. The binary toxin was detected in 12 (38.7%) and tcdC gene deletion in 3 (9.6%). CONCLUSIONS: The low specificity of QCC-EIA makes it less reliable as a confirmatory test for CDI diagnosis. This test may be used as a screening test in a two-step algorithm when combined with a molecular assay or another confirmatory test.

Clinical validation of 3 commercial real-time reverse transcriptase polymerase chain reaction assays for the detection of Middle East respiratory syndrome coronavirus from upper respiratory tract specimens.

Since discovery of Middle East respiratory syndrome coronavirus (MERS-CoV), a novel betacoronavirus first isolated and characterized in 2012, MERS-CoV real-time reverse transcriptase polymerase chain reaction (rRT-PCR) assays represent one of the most rapidly expanding commercial tests. However, in the absence of extensive evaluations of these assays on positive clinical material of different sources, evaluating their diagnostic effectiveness remains challenging. We describe the diagnostic performance evaluation of 3 common commercial MERS-CoV rRT-PCR assays on a large panel (n = 234) of upper respiratory tract specimens collected during an outbreak episode in Saudi Arabia. Assays were compared to the RealStar® MERS-CoV RT-PCR (Alton Diagnostics, Hamburg, Germany) assay as the gold standard. Results showed i) the TIB MolBiol® LightMix UpE and Orf1a assays (TIB MolBiol, Berlin, Germany) to be the most sensitive, followed by ii) the Anyplex™ Seegene MERS-CoV assay (Seegene, Seoul, Korea), and finally iii) the PrimerDesign™ Genesig® HCoV_2012 assay (PrimerDesign, England, United Kingdom). We also evaluate a modified protocol for the PrimerDesign™ Genesig® HCoV_2012 assay.

Predictors of MERS-CoV infection: A large case control study of patients presenting with ILI at a MERS-CoV referral hospital in Saudi Arabia.

BACKGROUND: A case control study to better characterize the clinical features, laboratory, and radiological abnormalities associated with MERS-CoV infection in order to help with early identification of this syndrome from other respiratory infections. METHODS: Eighty patients admitted to a hospital in Riyadh, diagnosed with MERS-CoV infection based on RT-PCR were matched on age, sex, and the presence of a co-morbid condition on a basis of 1:2 to other patients admitted with respiratory symptoms and tested negative for MERS-CoV on RT-PCR. RESULTS: None of the reported MERS-CoV presenting symptoms was significantly associated with being infected with MERS-CoV. On the other hand, WBC count was significantly lower in patients with confirmed MERS-CoV infection (median 5.7 vs 9.3, P: 0.0004). Neutrophil count was as well significantly lower in MERS-CoV patients (median 3.7 vs 6.7, P: 0.0001). Both AST, and ALT values were significantly higher in MERS-CoV infected group (AST median 42 vs 36, P: 0.03, and ALT median 33 vs 28, P: 0.003). Overall our MERS-CoV mortality rate was (10%) below the national figure of (40%). CONCLUSIONS: None of the presenting symptoms are specific for MERS-CoV infection. And out of all the investigations WBC, neutrophil counts, AST and ALT values have some predictive utility.