Respiratory syncytial virus (RSV) remains a major cause of severe respiratory disease in young children, and the rollout of vaccines and monoclonal antibodies has increased the importance of genomic surveillance. Here, we combined epidemiological analysis of 2,350 laboratory confirmed RSV infections recorded in the United Arab Emirates between 2018 and 2023 with genomic surveillance of 312 RSV positive clinical isolates collected during the 2023 to 2024 season, integrating global phylogenetic contextualization and model based variant prioritization. Severe RSV disease in the UAE was concentrated in infants and young children, who accounted for most hospital and intensive care admissions. Phylogenetic analysis showed that RSV circulation in the UAE was shaped by repeated introductions of globally circulating RSV-A and RSV-B lineages, followed by local transmission and diversification. UAE RSV-B variants also showed elevated model predicted escape burden relative to year and substitution count matched public sequences, with the strongest signals arising from a subset of circulating variants rather than the most common recurrent substitutions. Together, these findings highlight the value of surveillance in the UAE for understanding RSV circulation in a globally connected setting and show how integrated epidemiological, genomic, and evolutionary analyses can prioritize variants for continued surveillance and experimental evaluation.

Background: Wastewater systems provide an integrated One Health perspective on antimicrobial resistance but remain uneven globally, with limited data from rapidly urbanizing and highly connected regions such as the Arabian Gulf. Methods: An eight-month prospective study was conducted in Dubai, United Arab Emirates, with monthly sampling from nine community and two hospital nodes and two wastewater treatment plants (WWTP). Samples were analysed using high-throughput quantitative PCR (HT-qPCR; Resistomap, Finland) with a 72-target One Health gene panel. Results: Across the 120 samples analyzed, the number of detected gene targets ranged from 26 to 68 genes, with the highest diversity in hospital wastewater and the lowest in WWTP effluent. Pathogen-associated markers were detected in all sources, with enterococci, Escherichia coli, and Klebsiella pneumoniae predominant. Hospital wastewater showed broader pathogen-associated gene markers, including those linked to Acinetobacter baumannii and Pseudomonas aeruginosa. Antibiotic resistance genes (ARGs) associated with macrolide-lincosamide-streptogramin B, tetracycline, and aminoglycoside resistance were widespread. Community and influent samples were dominated by msrE, tet(M), and aminoglycoside resistance genes, whereas hospital wastewater showed the highest ARG burden, including enrichment of aac(6')-Ib, qnrS2, blaGES, blaTEM, blaKPC-2, and blaIMP-1. Several ARGs, including mcr-1, persisted in WWTP effluent. Mobile genetic elements (MGEs) were ubiquitous, with integron-associated markers prominent in WWTP effluent. ARG-MGE network analysis demonstrated extensive co-occurrence, with MGEs as central hubs linking multiple ARGs. Conclusions: Wastewater captures distinct resistome profiles across urban compartments, supporting its role for AMR surveillance. The persistence of ARGs and MGEs in WWTP effluent highlights the potential for environmental dissemination, through reuse of treated wastewater.

Background/Objectives: Wastewater-based antimicrobial resistance (AMR) surveillance typically relies on treatment plant influent as a single integrated matrix, obscuring source-specific signals. In arid settings where treated effluent is reused, understanding how resistomes and virulomes are structured across wastewater compartments is essential for One Health monitoring. Methods: Shotgun metagenomic sequencing was applied to 57 wastewater samples collected in Dubai, United Arab Emirates, between October 2024 and January 2025. Samples represented nine community sewer nodes, two tertiary-care hospital outflows, and influent and effluent from two wastewater treatment plants (WWTP). Datasets were used for taxonomic, resistome, and virulome profiling. Alpha diversity was compared using Wilcoxon rank-sum tests, beta-diversity differences were assessed using permutational multivariate analysis of variance, and source-associated AMR genes were identified using linear discriminant analysis effect size analysis. Results: A total of 1470 bacterial species, 822 antimicrobial resistance genes (ARGs), and 1554 virulence factor genes were identified. Bacterial diversity was significantly lower in WWTP effluent than in other compartments. Hospital wastewater was enriched for class D β-lactamases, including multiple blaOXA variants, whereas community wastewater and WWTP influent shared dominant macrolide and aminoglycoside resistance genes including msr(E), mph(E), strB and aadA1. Despite marked reductions in bacterial diversity after treatment, no significant difference in ARG diversity was observed between WWTP influent and WWTP effluent (p = 0.558), with resistance genes such as blaVEB, msr(E), mph(E) detected in the latter. Virulome profiles shifted from fimbrial gene dominance in untreated sources toward biofilm- and persistence-associated genes in WWTP effluent. ARG alpha diversity varied over time, whereas taxonomic and virulome diversity remained stable. Conclusions: Community and influent wastewater capture population-level AMR carriage, hospital outflows concentrate clinically relevant resistance determinants, and WWTP effluent retains resistance markers despite microbial biomass reduction. Compartment-resolved metagenomic surveillance provides a practical One Health framework for identifying high-value monitoring points.

Methicillin-resistant Staphylococcus aureus (MRSA) has moved beyond healthcare settings and is increasingly documented in food, yet genomic data from the Arabian Peninsula are scarce. This study aimed to characterize the genomic diversity, antimicrobial-resistance (AMR), and virulence repertoire of MRSA in retail red meat sold in Dubai, United Arab Emirates (UAE), and to evaluate evidence for potential human-to-food transmission. In a cross-sectional survey (September 2024 - February 2025), 140 red-meat samples (beef, mutton, camel) were collected from supermarket chains. Fifty-one MRSA isolates were confirmed by multiplex PCR and phenotypic testing. Short-read whole-genome sequencing was followed by bioinformatic characterization of the isolates for clonal complex (CC) multilocus sequence typing (ST), spa typing, SCCmec assignment, AMR and virulence genes identification, plasmid-replicon detection, and core-genome phylogeny. Genotype, meat commodity, and products' origin associations were statistically assessed. Eight sequence types were detected; CC5-ST6 (27.5 %) and CC8-ST789 (23.5 %) predominated. SCCmec IV and V accounted for 82.3 % of genomes, and no livestock-associated CC398 was found. CC5/ST6-t304 and CC8-t091 comprised 47 % of isolates but showed no association with meat type (p = 0.451). Core-genome analysis split the collection into six clusters with shallow branch lengths, signaling recent clonal expansion across local and imported meat products. All genomes carried the methicillin resistance mecA gene plus a median of five additional resistance genes; 41 % carried multidrug-resistant determinants. Classical enterotoxin genes occurred in 80.4 % of isolates, and Panton-Valentine leukocidin genes in 27.5 %, mainly within CC8 and CC22. Distinct plasmid backbones-RepA_N-RepL-Rep_trans in CC5-ST6 and Inc18-Rep3 in CC8-ST789-were associated with lineage-specific AMR profiles. Retail red meat in the UAE is contaminated by clinically important, community-associated MRSA clones, likely introduced via human handling rather than animal reservoirs. Genomic surveillance at the human-food interface can guide regional One Health policies and help curb foodborne antimicrobial resistance dissemination.

Wastewater-based surveillance (WBS) is valuable for monitoring antimicrobial resistance (AMR). Staphylococci are key targets, as wastewater can facilitate gene transfer and resistance emergence. Data on WBS for population-level AMR in the Arabian-Gulf remain limited. This study assessed Staphylococcus diversity and resistance in Dubai wastewater. Samples were collected over eight months from nine community sites, two hospital nodes, and two wastewater treatment plants (WWTPs) and were analysed by culture-based method. Ninety-six Staphylococcus isolates were recovered from community, hospital, and WWTP influent, with no growth in effluent. Most isolates (n/N = 88/96) were coagulase-negative Staphylococcus (CoNS), spanning 15 species, dominated by S. saprophyticus, S. cohnii and S. sciuri. The only coagulase-positive Staphylococcus was S. aureus (n = 8) and the only species detected across all wastewater sources. Resistance was highest to benzylpenicillin (88%) and fusidic acid (82%), whereas all isolates remained susceptible to glycopeptides, tigecycline, and linezolid. Fusidic acid resistance was higher in community-wastewater isolates, whereas β-lactam resistance predominated in hospital-wastewater isolates. Sixty percent of CoNS were multidrug-resistant; methicillin resistance occurred in 37.5% of CoNS and 50% of S. aureus. Wastewater is a reservoir of diverse multidrug-resistant staphylococci, underscoring One Health relevance reflecting the potential for circulation between humans, animals, and the shared environment. WBS can support population-level AMR monitoring to inform public health and veterinary interventions.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant burden globally, particularly in the Arabian Gulf region. The United Arab Emirates (UAE) has experienced rising MRSA prevalence, with increasing diversity in the clonal complexes (CCs) identified. The COVID-19 pandemic, with its increased hospitalization rates and antibiotic use, may have further influenced MRSA’s genetic evolution and epidemiology in the country. Methods: To investigate this influence, genomic profiling of 310 MRSA clinical isolates collected between February and November 2022 was performed using a DNA microarray-based assay. Results: Isolates were assigned to 22 clonal complexes and 72 distinct strain assignments. The predominant clonal complexes were CC5, CC6, CC361, CC22, CC1, and CC8. Community-acquired MRSA lineages were dominant, with only one healthcare-associated MRSA lineage isolate identified. Upward trends of CC1153 were observed along with rare CCs, such as CC121-MRSA and CC7-MRSA, with the latter being reported for the first time in the Arabian Gulf region. The presence of pandemic strains USA300 CC8-MRSA-[IVa + ACME1] and CC8-MRSA-IV strains were also observed, including variants lacking Panton–Valentine leukocidin (pvl) genes and missing tst1 or enterotoxin genes. The PVL-negative CC772-MRSA-V/VT was identified, representing its first report in the UAE. A novel variant, CC361-MRSA-IV (tst1+/PVL+), was identified. Pvl genes were observed in 36% of the isolates, primarily from skin and soft tissue infections, while fusC (SCC-borne fusidic acid resistance) was identified in 13% of the isolates. Conclusions: The findings highlight the ongoing evolution of MRSA in the UAE, with the persistence and emergence of diverse and rare clonal complexes, driving the need for continuous genomic surveillance.

Streptococcus pneumoniae is a significant cause of bacterial infections, including pneumonia, meningitis and septicemia, primarily affecting children, the elderly and immunocompromised individuals. This study aimed to elucidate the serotype and lineage distribution and molecular mechanisms underlying pneumococcal invasiveness through a comprehensive pangenomic analysis of 1416 isolates from Malawi. Our analysis comprised 810 isolates from asymptomatic carriers and 606 isolates from patients with bacteraemia or meningitis. We identified 58 serotypes, with serotypes 1, 5 and 12F exhibiting significantly higher prevalence among patients. These serotypes likely exhibit reduced nasopharyngeal colonization and demonstrate rapid dissemination to sterile sites. Notably, these serotypes form a distinct lineage with distinct genomic characteristics, including the absence of V-type ATP synthase. The pangenome analysis revealed two highly conserved surface protein complexes, F-type ATP synthase and SecA1-SecY, which deserve further investigation as potential targets for novel therapeutic interventions.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a global public health concern, including within the Gulf Cooperation Council (GCC). As an opportunistic pathogen, MRSA poses a threat to hospitalized patients, and to the wider community. Its success is largely attributed to its diverse virulence factors and adaptability, with antimicrobial resistance further enhancing its persistence and complicating treatment efforts. In the GCC, the epidemiology of MRSA is influenced by several distinctive factors, including the region’s diverse demographics, high population mobility, and variations in healthcare infrastructure. Understanding the molecular epidemiology is crucial to curb transmission and guide effective public health measures.AimThis scoping review evaluates MRSA data in GCC countries—United Arab Emirates (UAE), Saudi Arabia, Kuwait, Qatar, Oman, and Bahrain—focusing on prevalence trends, molecular characteristics, and gaps in the literature.MethodsA systematic search of the PubMed (National Library of Medicine [NLM], National Institutes of Health [NIH]) database was conducted to identify literature published between January 2010 and July 2025, using predefined keywords on MRSA epidemiology. Eligible studies were reviewed for MRSA prevalence, clonal diversity, antimicrobial resistance patterns, and virulence profiles.ResultsOf 864 records screened, 97 met the inclusion criteria and were subjected to detailed review. Most studies originated from Saudi Arabia (58%), followed by Kuwait (26%), UAE (7%), Oman (3%), Qatar (2%), Bahrain (2%), and two involving adjacent countries (2%). Data indicate a predominance of community-associated MRSA (CA-MRSA) across both healthcare and community settings. Several studies reported novel or rare MRSA strains across various GCC countries. Moreover, there is clear evidence of widespread resistance to multiple classes of antibiotics, highlighting the growing concern of multidrug-resistant MRSA. Increasing prevalence of strains with virulence/resistance genes such as pvl and SCCmec+fusC, associated with enhanced pathogenicity and resistance, was also observed. Along with wide clonal diversity, frequent travel, and differing infection control practices contribute to the region’s complex MRSA epidemiology.ConclusionMRSA in the GCC shows dynamic and evolving patterns. Continuous surveillance through coordinated regional efforts is essential. A One Health approach, combined with strengthened antimicrobial stewardship, mandatory hospital screenings, and wastewater monitoring, could improve MRSA detection, tracking, and control across the region.

Background The aim of this study was to characterize the epidemiology of human seasonal coronaviruses (HCoVs) in southern Malawi.Methods We tested for HCoVs 229E, OC43, NL63, and HKU1 using real-time polymerase chain reaction (PCR) on upper respiratory specimens from asymptomatic controls and individuals of all ages recruited through severe acute respiratory illness (SARI) surveillance at Queen Elizabeth Central Hospital, Blantyre, and a prospective influenza-like illness (ILI) observational study between 2011 and 2017. We modeled the probability of having a positive PCR for each HCoV using negative binomial models, and calculated pathogen-attributable fractions (PAFs).Results Overall, 8.8% (539/6107) of specimens were positive for >= 1 HCoV. OC43 was the most frequently detected HCoV (3.1% [191/6107]). NL63 was more frequently detected in ILI patients (adjusted incidence rate ratio [aIRR], 9.60 [95% confidence interval {CI}, 3.25-28.30]), while 229E (aIRR, 8.99 [95% CI, 1.81-44.70]) was more frequent in SARI patients than asymptomatic controls. In adults, 229E and OC43 were associated with SARI (PAF, 86.5% and 89.4%, respectively), while NL63 was associated with ILI (PAF, 85.1%). The prevalence of HCoVs was similar between children with SARI and controls. All HCoVs had bimodal peaks but distinct seasonality.Conclusions OC43 was the most prevalent HCoV in acute respiratory illness of all ages. Individual HCoVs had distinct seasonality that differed from temperate settings. Human seasonal coronaviruses (HCoVs) were prevalent among children and adults with mild and severe acute respiratory illness (SARI) in Malawi between 2011 and 2017. 229E and OC43 were associated with SARI, and NL63 with influenza-like illness. Individual HCoVs had distinct seasonality.

IntroductionThe Centers for Disease Prevention and Control lists Candida auris, given its global emergence, multidrug resistance, high mortality, and persistent transmissions in health care settings as one of five urgent threats. As a new threat, the need for surveillance of C. auris is critical. This is particularly important for a cosmopolitan setting and global hub such as the United Arab Emirates (UAE) where continued introduction and emergence of resistant variant strains is a major concern.MethodsThe United Arab Emirates has carried out a 12 years of antimicrobial resistance surveillance (2010–2021) across the country, spanning all seven Emirates. A retrospective analysis of C. auris emergence from 2018–2021 was undertaken, utilising the demographic and microbiological data collected via a unified WHONET platform for AMR surveillance.ResultsNine hundred eight non-duplicate C. auris isolates were reported from 2018–2021. An exponential upward trend of cases was found. Most isolates were isolated from urine, blood, skin and soft tissue, and the respiratory tract. UAE nationals nationals comprised 29% (n = 186 of 632) of all patients; the remainder were from 34 other nations. Almost all isolates were from inpatient settings (89.0%, n = 809). The cases show widespread distribution across all reporting sites in the country. C. auris resistance levels remained consistently high across all classes of antifungals used. C. auris in this population remains highly resistant to azoles (fluconazole, 72.6% in 2021) and amphotericin. Echinocandin resistance has now emerged and is increasing annually. There was no statistically significant difference in mortality between Candida auris and Candida spp. (non-auris) patients (p-value: 0.8179), however Candida auris patients had a higher intensive care unit (ICU) admission rate (p-value <0.0001) and longer hospital stay (p < 0.0001) compared to Candida spp. (non-auris) patients.ConclusionThe increasing trend of C. auris detection and associated multidrug resistant phenotypes in the UAE is alarming. Continued C. auris circulation in hospitals requires enhanced infection control measures to prevent continued dissemination.

The United Arab Emirates has very little data on the incidence or prevalence of fungal diseases. Using total and underlying disease risk populations and likely affected proportions, we have modelled the burden of fungal disease for the first time. The most prevalent serious fungal conditions are recurrent vulvovaginitis (~190,000 affected) and fungal asthma (~34,000 affected). Given the UAE’s low prevalence of HIV, we estimate an at-risk population of 204 with respect to serious fungal infections with cryptococcal meningitis estimated at 2 cases annually, 15 cases of Pneumocystis pneumonia (PCP) annually, and 20 cases of esophageal candidiasis in the HIV population. PCP incidence in non-HIV patients is estimated at 150 cases annually. Likewise, with the same low prevalence of tuberculosis in the country, we estimate a total chronic pulmonary aspergillosis prevalence of 1002 cases. The estimated annual incidence of invasive aspergillosis is 505 patients, based on local data on rates of malignancy, solid organ transplantation, and chronic obstructive pulmonary disease (5.9 per 100,000). Based on the 2022 annual report of the UAE’s national surveillance database, candidaemia annual incidence is 1090 (11.8/100,000), of which 49.2% occurs in intensive care. Fungal diseases affect ~228,695 (2.46%) of the population in the UAE.

Objective Microbial keratitis (MK) is a significant cause of blindness in sub-Saharan Africa. We investigated the feasibility of using a novel corneal impression membrane (CIM) for obtaining and processing samples by culture, PCR and whole-genome sequencing (WGS) in patients presenting with suspected MK in Malawi.Methods and analysis Samples were collected from patients presenting with suspected MK using a 12 mm diameter polytetrafluoroethylene CIM disc. Samples were processed using culture and PCR for Acanthamoeba, herpes simplex virus type 1 (HSV-1) and the bacterial 16S rRNA gene. Minimum inhibitory concentrations of isolates to eight antimicrobials were measured using susceptibility strips. WGS was used to characterise Staphylococcus aureus isolates.Results 71 eyes of 71 patients were included. The overall CIM isolation rate was 81.7% (58 positive samples from 71 participants). 69 (81.2%) of isolates were Gram-positive cocci. Coagulase-negative Staphylococcus 31.8% and Streptococcus species 14.1% were the most isolated bacteria. Seven (9.9%) participants were positive for HSV-1. Fungi and Acanthamoeba were not detected. Moxifloxacin and chloramphenicol offered the best coverage for both Gram-positive and Gram-negative isolates when susceptibility was determined using known antimicrobial first quartile concentrations and European Committee on Antimicrobial Susceptibility Testing breakpoints, respectively. WGS identified known virulence genes associated with S. aureus keratitis.Conclusions In a resource-poor setting, a CIM can be used to safely sample the cornea in patients presenting with suspected MK, enabling identification of causative microorganisms by culture and PCR. Although the microbiological spectrum found was limited to the dry season, these preliminary results could be used to guide empirical treatment.

Surveillance methods of circulating antibiotic resistance genes (ARGs) are of utmost importance in order to tackle what has been described as one of the greatest threats to humanity in the 21st century. In order to be effective, these methods have to be accurate, quickly deployable, and scalable. In this study, we compare metagenomic shotgun sequencing (TruSeq DNA sequencing) of wastewater samples with a state-of-the-art PCR-based method (Resistomap HT-qPCR) on four wastewater samples that were taken from hospital, industrial, urban and rural areas. ARGs that confer resistance to 11 antibiotic classes have been identified in these wastewater samples using both methods, with the most abundant observed classes of ARGs conferring resistance to aminoglycoside, multidrug-resistance (MDR), macrolide-lincosamide-streptogramin B (MLSB), tetracycline and beta-lactams. In comparing the methods, we observed a strong correlation of relative abundance of ARGs obtained by the two tested methods for the majority of antibiotic classes. Finally, we investigated the source of discrepancies in the results obtained by the two methods. This analysis revealed that false negatives were more likely to occur in qPCR due to mutated primer target sites, whereas ARGs with incomplete or low coverage were not detected by the sequencing method due to the parameters set in the bioinformatics pipeline. Indeed, despite the good correlation between the methods, each has its advantages and disadvantages which are also discussed here. By using both methods together, a more robust ARG surveillance program can be established. Overall, the work described here can aid wastewater treatment plants that plan on implementing an ARG surveillance program.

Invasive non-typhoidal Salmonella (iNTS) disease is a serious bloodstream infection that targets immune-compromised individuals, and causes significant mortality in sub-Saharan Africa. Salmonella enterica serovar Typhimurium ST313 causes the majority of iNTS in Malawi. We performed an intensive comparative genomic analysis of 608 S. Typhimurium ST313 isolates dating between 1996 and 2018 from Blantyre, Malawi. We discovered that following the arrival of the well-characterized S. Typhimurium ST313 lineage 2 in 1999, two multidrug-resistant variants emerged in Malawi in 2006 and 2008, designated sublineages 2.2 and 2.3, respectively. The majority of S. Typhimurium isolates from human bloodstream infections in Malawi now belong to sublineages 2.2 or 2.3. To understand the emergence of the prevalent ST313 sublineage 2.2, we studied two representative strains, D23580 (lineage 2) and D37712 (sublineage 2.2). The chromosome of ST313 lineage 2 and sublineage 2.2 only differed by 29 SNPs/small indels and a 3 kb deletion of a Gifsy-2 prophage region including the sseI pseudogene. Lineage 2 and sublineage 2.2 had distinctive plasmid profiles. The transcriptome was investigated in 15 infection-relevant in vitro conditions and within macrophages. During growth in physiological conditions that do not usually trigger S. Typhimurium SPI2 gene expression, the SPI2 genes of D37712 were transcriptionally active. We identified down-regulation of flagellar genes in D37712 compared with D23580. Following phenotypic confirmation of transcriptomic differences, we discovered that sublineage 2.2 had increased fitness compared with lineage 2 during mixed growth in minimal media. We speculate that this competitive advantage is contributing to the emergence of sublineage 2.2 in Malawi.

IntroductionMethicillin resistant Staphylococcus aureus (MRSA) is a major contributor to the global burden of antimicrobial resistance (AMR). As MRSA continues to evolve, the need for continued surveillance to evaluate trends remains crucial. This study was carried out to assess MRSA trends in the United Arab Emirates (UAE) based on analysis of data from the national AMR surveillance program.MethodsWe carried out a 12-year (2010–2021) retrospective analysis of MRSA demographic and microbiological data collected as part of the UAE national AMR surveillance program. Participating centers from across the country routinely submit AMR surveillance data collected by trained personnel to the National AMR Surveillance Committee, where data is analyzed using a unified WHONET platform. Data on non-duplicate isolates associated with clinical infections were obtained and included in the analysis.ResultsA total of 29,414 non-duplicate MRSA isolates associated with clinical infections were reported between 2010 and 2021 (2010: n = 259; 2021: n = 4,996). MRSA represented 26.4% of all S. aureus (n = 111,623) isolates identified during the study period. In 2010, among the S. aureus isolates with reported oxacillin testing, 21.9% (n/N = 259/1,181) were identified as MRSA and this showed an increase to 33.5% (n/N = 4,996/14,925) in 2021. Although there was variation in the distribution of MRSA across the seven emirates of the country, most had an upward trend. Patient demographics reflected a male preponderance, with most being adults and from the outpatient setting. Isolates were mostly from skin and soft tissue infection specimens (72.5%; n/N = 21,335/29,414). Among the inpatients (N = 8,282), a total of 3,313 MRSA isolates were from specimens obtained ≤ 48 h after admission indicative of community acquired infection. Increasing resistance trends were observed for most antibiotics including ciprofloxacin, levofloxacin, moxifloxacin, erythromycin, gentamicin, trimethoprim-sulfamethoxazole, and quinupristin/dalfopristin. Low levels of resistance (0.0–0.8%) were sustained for linezolid except for 2015, 2016, and 2017 with 2.5, 2.6, and 2.9%, respectively. No confirmed vancomycin resistance was reported.ConclusionThe increasing trend of MRSA isolates associated with clinical infections in the hospital and community settings is a concern. Continued monitoring including incorporation of genomic surveillance and infection control measures are recommended to stem the dissemination.

IntroductionAlthough pneumococcal conjugate vaccines (PCV) have been effective in reducing the burden of Streptococcus pneumoniae infections, there is a paucity of data on the relationship with antimicrobial resistance (AMR) trends in the Arabian Gulf region. This study was carried out to assess S. pneumoniae resistance trends in the United Arab Emirates (UAE) where PCV-13 vaccination was introduced in 2011.MethodsRetrospective analysis of S. pneumoniae demographic and microbiological data collected as part of the national AMR surveillance program from 2010 to 2021 was carried out. A survey of reporting sites and hand searching of annual reports of local health authorities was carried out to identify data on S. pneumoniae serotypes as this is not included in the AMR surveillance database.ResultsFrom 2010 to 2021, 11,242 non-duplicate S. pneumoniae isolates were reported, increasing from 324 in 2010 to 1,115 in 2021. Factoring in annual increment in the number of surveillance sites, the number of isolates per site showed an upward trajectory from 2015 to 2018 and declined in 2020 with the onset of the pandemic. The majority of isolates (n/N = 5,751/11,242; 51.2%) were from respiratory tract specimens with 44.5% (n/N = 2,557/5,751) being nasal colonizers. Up to 11.9% (n/N = 1,337/11,242) were invasive pneumococcal disease (IPD) isolates obtained from sterile site specimens including blood (n = 1,262), cerebrospinal (n = 52), pleural (n = 19) and joint (n = 4) fluid; and were predominantly from pediatric patients. The downward trend for amoxicillin and for penicillin G at the non-meningitis and meningitis as well as oral penicillin breakpoints was statistically significant. In contrast, increasing trends of resistance were seen for levofloxacin, moxifloxacin, trimethoprim/sulfamethoxazole and erythromycin. IPD and non-IPD isolates showed similar demographic and AMR trends. None of the surveillance sites carried out S. pneumoniae serotyping and handsearching of annual reports did not yield this information.ConclusionThe increasing trend of pneumococcal disease and AMR with emergence of isolates with MDR phenotype despite is of concern. In the absence of S. pneumoniae serotyping the role of non-vaccine serotypes in driving this pattern remains unknown. There is an urgent need for serotype, genomic and AMR surveillance of S. pneumoniae isolates in the UAE.

Pneumococcal serotype 35B is an important non- conjugate vaccine (non- PCV) serotype. Its continued emergence, post- PCV7 in the USA, was associated with expansion of a pre- existing 35B clone (clonal complex [CC] 558) along with post- PCV13 emergence of a non- 35B clone previously associated with PCV serotypes (CC156). This study describes lineages circulating among 35B isolates in South Africa before and after PCV introduction. We also compared 35B isolates belonging to a predominant 35B lineage in South Africa (GPSC5), with isolates belonging to the same lineage in other parts of the world. Serotype 35B isolates that caused invasive pneumococcal disease in South Africa in 2005-2014 were characterized by whole- genome sequencing (WGS). Multi- locus sequence types and global pneumococcal sequence clusters (GPSCs) were derived from WGS data of 63 35B isolates obtained in 2005-2014. A total of 262 isolates that belong to GPSC5 (115 isolates from South Africa and 147 from other countries) that were sequenced as part of the global pneumococcal sequencing (GPS) project were included for comparison. Serotype 35B isolates from South Africa were differentiated into seven GPSCs and GPSC5 was most common (49 %, 31/63). While 35B was the most common serotype among GPSC5/CC172 isolates in South Africa during the PCV13 period (66 %, 29/44), 23F was the most common serotype during both the pre- PCV (80 %, 37/46) and PCV7 period (32 %, 8/25). Serotype 35B represented 15 % (40/262) of GPSC5 isolates within the global GPS database and 75 % (31/40) were from South Africa. The predominance of the GPSC5 lineage within non- vaccine serotype 35B, is possibly unique to South Africa and warrants further molecular surveillance of pneumococci.

Objective Assess characteristics of clinical pneumonia after introduction of pneumococcal conjugate vaccine (PCV), by HIV exposure status, in children hospitalised in a governmental hospital in Malawi. Methods and findings We evaluated 1139 children ≤5 years old hospitalised with clinical pneumonia: 101 HIV-exposed, uninfected (HEU) and 1038 HIV-unexposed, uninfected (HUU). Median age was 11 months (IQR 6–20), 59% were male, median mid-upper arm circumference (MUAC) was 14 cm (IQR 13–15) and mean weight-for-height z score was −0.7 (±2.5). The highest Respiratory Index of Severity in Children (RISC) scores were allocated to 10.4% of the overall cohort. Only 45.7% had fever, and 37.2% had at least one danger sign at presentation. The most common clinical features were crackles (54.7%), nasal flaring (53.5%) and lower chest wall indrawing (53.2%). Compared with HUU, HEU children were significantly younger (9 months vs 11 months), with lower mean birth weight (2.8 kg vs 3.0 kg) and MUAC (13.6 cm vs 14.0 cm), had higher prevalence of vomiting (32.7% vs 22.0%), tachypnoea (68.4% vs 49.8%) and highest RISC scores (20.0% vs 9.4%). Five children died (0.4%). However, clinical outcomes were similar for both groups. Conclusions In this post-PCV setting where prevalence of HIV and malnutrition is high, children hospitalised fulfilling the WHO Integrated Management of Childhood Illness criteria for clinical pneumonia present with heterogeneous features. These vary by HIV exposure status but this does not influence either the frequency of danger signs or mortality. The poor performance of available severity scores in this population and the absence of more specific diagnostics hinder appropriate antimicrobial stewardship and the rational application of other interventions.

Group A Streptoccocus (GAS) is among the most diverse of all human pathogens, responsible for a range of clinical manifestations, from mild superficial infections such as pharyngitis to serious invasive infections such as necrotising fasciitis and sepsis. The drivers of these different disease phenotypes are not known. The GAS cholesterol-dependent cytolysin, Streptolysin O (SLO), has well established cell and tissue destructive activity. We investigated the role of SLO in determining disease outcome in vivo, by using two different clinical lineages; the recently emerged hypervirulent outbreak emm type 32.2 strains, which result in sepsis, and the emm type 1.0 strains which cause septic arthritis. Using clinically relevant in vivo mouse models of sepsis and a novel septic arthritis model, we found that the amount and activity of SLO was vital in determining the course of infection. The emm type 32.2 strain produced large quantities of highly haemolytic SLO that resulted in rapid development of sepsis. By contrast, the reduced concentration and lower haemolytic activity of emm type 1.0 SLO led to translocation of bacteria from blood to joints. Importantly, sepsis associated strains that were attenuated by deletion or inhibition of SLO, then also translocated to the joint, confirming the key role of SLO in determining infection niche. Our findings demonstrate that SLO is key to in vivo phenotype and disease outcome. Careful consideration should be given to novel therapy or vaccination strategies that target SLO. Whilst neutralising SLO activity may reduce severe invasive disease, it has the potential to promote chronic inflammatory conditions such as septic arthritis.