Re-infection with a different SARS-CoV-2 clade and prolonged viral shedding in a hematopoietic stem cell transplantation patient.

Immunocompromised patients who have a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection pose many clinical and public health challenges. We describe the case of a hematopoietic stem cell transplantation patient with lymphoma who had a protracted illness requiring three consecutive hospital admissions. Whole genome sequencing confirmed two different SARS-CoV-2 clades. Clinical management issues and the unanswered questions arising from this case are discussed.

Development and Optimization of In-house ELISA for Detection of Human IgG Antibody to SARS-CoV-2 Full Length Spike Protein.

The ongoing coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a threat to human health. Despite this, many affected countries are now in the process of gradual lifting of COVID-19 restrictions that were initially implemented in response to the pandemic. The success of the so-called "exit strategy" requires continued surveillance of virus circulation in the community and evaluation of the prevalence of protective immunity among population. Serology tests are valuable tools for these purposes. Herein, SARS-CoV-2 full-length spike (S) recombinant protein was utilized to develop and optimize an indirect enzyme-linked immunoassay (ELISA) that enables a reliable detection of virus-specific IgG antibody in human sera. Importantly, the performance of this assay was evaluated utilizing micro-neutralization (MN) assay as a reference test. Our developed ELISA offers 100% sensitivity, 98.4% specificity, 98.8% agreement, and high overall accuracy. Moreover, the optical density (OD) values of positive samples significantly correlated with their MN titers. The assay specifically detects human IgG antibodies directed against SARS-CoV-2, but not those to Middle East respiratory syndrome coronavirus (MERS-CoV) or human coronavirus HKU1 (HCoV-HKU1). The availability of this in-house ELISA protocol would be valuable for various diagnostic and epidemiological applications.

Genomic and antimicrobial resistance genes diversity in multidrug-resistant CTX-M-positive isolates of Escherichia coli at a health care facility in Jeddah.

BACKGROUND: Whole genome sequencing has revolutionized epidemiological investigations of multidrug-resistant pathogenic bacteria worldwide. Aim of this study was to perform comprehensive characterization of ESBL-positive isolates of Escherichia coli obtained from clinical samples at the King Abdulaziz University Hospital utilizing whole genome sequencing. METHODS: Isolates were identified by MALDI-TOF mass spectrometry. Genome sequencing was performed using a paired-end strategy on the MiSeq platform. RESULTS: Nineteen isolates were clustered into different clades in a phylogenetic tree based on single nucleotide polymorphisms in core genomes. Seventeen sequence types were identified in the extended-spectrum ß-lactamase (ESBL)-positive isolates, and 11 subtypes were identified based on distinct types of fimH alleles. Forty-one acquired resistance genes were found in the 19 genomes. The blaCTX-M-15 gene, which encodes ESBL, was found in 15 isolates and was the most predominant resistance gene. Other antimicrobial resistance genes (ARGs) found in the isolates were associated with resistance to tetracycline (tetA), aminoglycoside [aph(3″)-Ib, and aph(6)-Id], and sulfonamide (sul1, and sul2). Nonsynonymous chromosomal mutations in the housekeeping genes parC and gyrA were commonly found in several genomes. CONCLUSION: Several other ARGs were found in CTX-M-positive E. coli isolates confer resistance to clinically important antibiotics used to treat infections caused by Gram-negative bacteria.

Genetic characterization and diversity of circulating influenza A/H1N1pdm09 viruses isolated in Jeddah, Saudi Arabia between 2014 and 2015.

The emerged influenza A/H1N1pdm09 viruses have replaced the previously circulating seasonal H1N1 viruses. The close antigenic properties of these viruses to the 1918 H1N1 pandemic viruses and their post-pandemic evolution pattern could further enhance their adaptation and pathogenicity in humans representing a major public health threat. Given that data on the dynamics and evolution of these viruses in Saudi Arabia is sparse we investigated the genetic diversity of circulating influenza A/H1N1pdm09 viruses from Jeddah, Saudi Arabia, by analyzing 39 full genomes from isolates obtained between 2014-2015, from patients with varying symptoms. Phylogenetic analysis of all gene segments and concatenated genomes showed similar topologies and co-circulation of clades 6b, 6b.1 and 6b.2, with clade 6b.1 being the most predominate since 2015. Most viruses were more closely related to the vaccine strain (Michigan/45/2015) recommended for the 2017/2018 season, than to the California/07/2009 strain. Low sequence variability was observed in the haemagglutinin protein compared to the neuraminidase protein. Resistance to neuraminidase inhibitors was limited as only one isolate had the H275Y substitution. Interestingly, two isolates had short PA-X proteins of 206 amino acids compared to the 232 amino acid protein found in most influenza A/H1N1pdm09 viruses. Together, the co-circulation of several clades and the predominance of clade 6b.1, despite its low circulation in Asia in 2015, suggests multiple introductions most probably during the mass gathering events of Hajj and Umrah. Jeddah represents the main port of entry to the holy cities of Makkah and Al-Madinah, emphasizing the need for vigilant surveillance in the kingdom.

Phylogenetic characterization of circulating Dengue and Alkhumra Hemorrhagic Fever viruses in western Saudi Arabia and lack of evidence of Zika virus in the region: A retrospective study, 2010-2015.

Flaviviruses represent a global public health concern. They consist of ∼70 viruses with almost half of them causing human diseases with unspecified febrile illnesses. Cities in western Saudi Arabia are endemic for viruses (DENV) with sporadic infections due to Alkhumra hemorrhagic fever virus (AHFV). They also represent a major destination for travelers coming for annual religious pilgrimages (Hajj and Umrah) from all over the world. However, whether other flaviviruses are circulating is not known because of the limited number of surveillance studies. Here, we retrospectively screened 690 samples for flaviviruses in samples from patients with unexplained febrile illnesses between 2010 and 2015 in western Saudi Arabia using a pan-flaviviruses RT-PCR assay. Despite Zika virus RNA was not detected, this study confirms circulation and/or sporadic spread of DENV-2, DENV-3, and AHFV, higher prevalence of DENV-2, and a role for visitors from DENV endemic countries in DENV importation into the Kingdom. Further analysis also showed very low genetic diversity of AHFV confirming its slow microevolution. Accordingly, continuous and prospective surveillance for flaviviruses using such assay are warranted in Saudi Arabia which receives millions of Muslims annually to implement effective control measures in light of the global widespread and outbreaks of several flaviviruses.

Multiple Introductions of Dengue 2 Virus Strains into Saudi Arabia from 1992 to 2014.

INTRODUCTION: Dengue is a significant arboviral infection that represents a major public health concern worldwide. The infection is endemic in most parts of South East Asia, sub-Saharan Africa, and Latin America. Among the four dengue virus (DENV) serotypes, DENV-2 has been reported to be the predominant serotype in Saudi Arabia since 1992. However, virological and epidemiological data of DENV-2 from Saudi Arabia are severely deficient and require further investigations. METHODS: Full genome sequencing of a recent DENV-2 isolate and phylogenetic analysis of all available DENV-2 sequences from Saudi Arabia. RESULTS: Based on full genome and envelope (E) gene sequence, we show that a recent isolate (DENV-2-Jeddah-2014) belongs to the Indian subcontinent lineage of the Cosmopolitan genotype with close similarity to recent strains from Pakistan. Interestingly, the E gene sequence of DENV-2-Jeddah-2014 isolate was slightly divergent from those previously identified in Saudi Arabia between 1992 and 2004 with three to nine amino acid (aa) substitutions. While our data show that the Cosmopolitan genotype is still circulating in Saudi Arabia, they highlight four distinct genetic groups suggesting at least four independent introductions into the Kingdom. CONCLUSIONS: The close clustering of DENV-2 isolates reported from Saudi Arabia between 1992 and 2014 with strains from countries providing the highest numbers of pilgrims attending either Hajj or Umrah pilgrimages (Indonesia, Pakistan, India) clearly suggests a role for pilgrims or expatriates coming from DENV endemic countries in DENV-2 importation into Saudi Arabia. Accordingly, continuous monitoring of the circulation of DENVs in Saudi Arabia must be implemented to undertake effective control and management strategies in the Kingdom. Screening of the pilgrims coming to perform Hajj and Umrah might help prevent the introduction of new DENV strains, which is expected to increase the burden of the disease not only in Saudi Arabia but also in other countries.

Complete genome sequencing and phylogenetic analysis of dengue type 1 virus isolated from Jeddah, Saudi Arabia.

BACKGROUND: Dengue viruses (DENVs) are mosquito-borne viruses which can cause disease ranging from mild fever to severe dengue infection. These viruses are endemic in several tropical and subtropical regions. Multiple outbreaks of DENV serotypes 1, 2 and 3 (DENV-1, DENV-2 and DENV-3) have been reported from the western region in Saudi Arabia since 1994. Strains from at least two genotypes of DENV-1 (Asia and America/Africa genotypes) have been circulating in western Saudi Arabia until 2006. However, all previous studies reported from Saudi Arabia were based on partial sequencing data of the envelope (E) gene without any reports of full genome sequences for any DENV serotypes circulating in Saudi Arabia. FINDINGS: Here, we report the isolation and the first complete genome sequence of a DENV-1 strain (DENV-1-Jeddah-1-2011) isolated from a patient from Jeddah, Saudi Arabia in 2011. Whole genome sequence alignment and phylogenetic analysis showed high similarity between DENV-1-Jeddah-1-2011 strain and D1/H/IMTSSA/98/606 isolate (Asian genotype) reported from Djibouti in 1998. Further analysis of the full envelope gene revealed a close relationship between DENV-1-Jeddah-1-2011 strain and isolates reported between 2004-2006 from Jeddah as well as recent isolates from Somalia, suggesting the widespread of the Asian genotype in this region. CONCLUSIONS: These data suggest that strains belonging to the Asian genotype might have been introduced into Saudi Arabia long before 2004 most probably by African pilgrims and continued to circulate in western Saudi Arabia at least until 2011. Most importantly, these results indicate that pilgrims from dengue endemic regions can play an important role in the spread of new DENVs in Saudi Arabia and the rest of the world. Therefore, availability of complete genome sequences would serve as a reference for future epidemiological studies of DENV-1 viruses.