S. Enteritidis and S. Typhimurium Harboring SPI-1 and SPI-2 Are the Predominant Serotypes Associated With Human Salmonellosis in Saudi Arabia

Non-typhoidal Salmonella (NTS) strains are Gram negative bacterial pathogens that are associated with foodborne illness worldwide. During the process of infection, Salmonella uses two molecular injectisomes known as Type 3 Secretion Systems (T3SS) to secrete virulence factors that are encoded by Salmonella Pathogenicity Island-1 (SPI-1) and SPI-2 into host cells. These secretion systems play a major role in virulence, as shown in various animal models, but little is known about their role in human infections. In Saudi Arabia, NTS strains frequently cause human infections but data regarding these pathogenic strains is fairly limited. The aim of this study was to characterize Salmonella human clinical isolates in Riyadh, Saudi Arabia, by determining their serotype, testing for the presence of SPI-1 and SPI-2 genes and to determine the antibiotic resistance profiles of these strains. Using the rapid Check and Trace Salmonella™ (CTS) system our results demonstrate that S. Enteritidis and S. Typhimurium were the predominant serovars, followed by S. Livingstone, S. Kentucky and S. Poona among a list of 36 serovars reported for the first time in the country. In addition, SPI-1 genes were detected in 99% of the isolates, while the sifA gene (SPI-2) was not detected in 13.5% of the isolates. These results suggest that both the SPI-1 and SPI-2 virulence determinants are important for human infection. Moreover, we report the presence of a Multi-Drug (MDR) carbapenem resistant S. Kentucky isolate harboring the blaOXA−48 gene not reported previously in Saudi Arabia

Establishing a marine monitoring programme to assess antibiotic resistance: a case study from the Gulf Cooperation Council (GCC) region

The World Health Organization considers antimicrobial resistance as one of the most pressing global issues which poses a fundamental threat to human health, development, and security. Due to demographic and environmental factors, the marine environment of the Gulf Cooperation Council (GCC) region may be particularly susceptible to the threat of antimicrobial resistance. However, there is currently little information on the presence of AMR in the GCC marine environment to inform the design of appropriate targeted surveillance activities. The objective of this study was to develop, implement and conduct a rapid regional baseline monitoring survey of the presence of AMR in the GCC marine environment, through the analysis of seawater collected from high-risk areas across four GCC states: (Bahrain, Oman, Kuwait, and the United Arab Emirates). 560 Escherichia coli strains were analysed as part of this monitoring programme between December 2018 and May 2019. Multi-drug resistance (resistance to three or more structural classes of antimicrobials) was observed in 32.5% of tested isolates. High levels of reduced susceptibility to ampicillin (29.6%), nalidixic acid (27.9%), tetracycline (27.5%), sulfamethoxazole (22.5%) and trimethoprim (22.5%) were observed. Reduced susceptibility to the high priority critically important antimicrobials: azithromycin (9.3%), ceftazidime (12.7%), cefotaxime (12.7%), ciprofloxacin (44.6%), gentamicin (2.7%) and tigecycline (0.5%), was also noted. A subset of 173 isolates was whole genome sequenced, and high carriage rates of qnrS1 (60/173) and bla CTX-M-15 (45/173) were observed, correlating with reduced susceptibility to the fluoroquinolones and third generation cephalosporins, respectively. This study is important because of the resistance patterns observed, the demonstrated utility in applying genomic-based approaches to routine microbiological monitoring, and the overall establishment of a transnational AMR surveillance framework focussed on coastal and marine environments

The role of whole genome sequencing in monitoring antimicrobial resistance: A biosafety and public health priority in the Arabian Peninsula

The recent declaration by the United Nations to establish an interagency coordination group (IACG) on antimicrobial resistance (AMR) emphasises the global nature of the AMR threat. Rapid dissemination and spread of AMR is exacerbated by the movements of humans, animals, foods and materials. International monitoring and surveillance of AMR indicates to policy makers, regulators and auditors the magnitude of the problem and also informs appropriate and mindful interventions that will impact public health policy and mitigate AMR. Identifying the drivers of AMR requires a ‘one-health’ approach to capture cross-sectoral utilization, phenotypic and genetic data. Capacity building in diagnostic and reference laboratories is required for traditional phenotypic testing as well as newer technologies (e.g. whole genome sequencing, WGS), in order to enhance the detection, characterisation, tracking and surveillance of AMR. The Gulf Health Council (GHC) for the cooperation council states have developed national AMR plans and will standardise pathogen identification and susceptibility testing to gain useful, reliable and comparable data. Additional plans are to establish, for the region, a state-of-the-art ‘one-health’ WGS service to identify and examine emerging AMR issues as well as the associated healthcare and financial burden(s). Currently, there is a paucity of WGS based research for tackling AMR challenges in the GHC countries. In this article, we have considered the current surveillance landscape and the potential role of whole genome sequencing (WGS) for monitoring antimicrobial resistance in the Arabian Peninsula. We highlighted the importance of using WGS for monitoring AMR in these countries as there remains a dearth of microbial genomic data and studies from the GHC countries. Development of WGS-based AMR surveillance is required to identify the burden and prevalence of AMR in the GHC countries. Keywords: Antibiotics, Drug-resistant infections, Clinical microbiology, Whole genome Sequencing, Infection prevention and control, Public Health, Gulf Health Council (GHC

Antibacterial Efficacy of Liposomal Formulations Containing Tobramycin and <i>N</i>-Acetylcysteine against Tobramycin-Resistant <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i>, and <i>Acinetobacter baumannii</i>

The antibacterial activity and biofilm reduction capability of liposome formulations encapsulating tobramycin (TL), and Tobramycin-N-acetylcysteine (TNL) were tested against tobramycin-resistant strains of E. coli, K. pneumoniae and A. baumannii in the presence of several resistant genes. All antibacterial activity were assessed against tobramycin-resistant bacterial clinical isolate strains, which were fully characterized by whole-genome sequencing (WGS). All isolates acquired one or more of AMEs genes, efflux pump genes, OMP genes, and biofilm formation genes. TL formulation inhibited the growth of EC_089 and KP_002 isolates from 64 mg/L and 1024 mg/L to 8 mg/L. TNL formulation reduced the MIC of the same isolates to 16 mg/L. TNL formulation was the only effective formulation against all A. baumannii strains compared with TL and conventional tobramycin (in the plektonic environment). Biofilm reduction was significantly observed when TL and TNL formulations were used against E. coli and K. pneumoniae strains. TNL formulation reduced biofilm formation at a low concentration of 16 mg/L compared with TL and conventional tobramycin. In conclusion, TL and TNL formulations particularly need to be tested on animal models, where they may pave the way to considering drug delivery for the treatment of serious infectious diseases

Learning from mistakes: the role of phages in pandemics

The misuse of antibiotics is leading to the emergence of multidrug-resistant (MDR) bacteria, and in the absence of available treatments, this has become a major global threat. In the middle of the recent severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic, which has challenged the whole world, the emergence of MDR bacteria is increasing due to prophylactic administration of antibiotics to intensive care unit patients to prevent secondary bacterial infections. This is just an example underscoring the need to seek alternative treatments against MDR bacteria. To this end, phage therapy has been proposed as a promising tool. However, further research in the field is mandatory to assure safety protocols and to develop appropriate regulations for its use in clinics. This requires investing more in such non-conventional or alternative therapeutic approaches, to develop new treatment regimens capable of reducing the emergence of MDR and preventing future global public health concerns that could lead to incalculable human and economic losses.This research was funded by ESCMID Research Grant 20200063 to PD-C, and Program to monitor antimicrobial resistance and develop antimicrobial agents King Abdullah International Medical Research Center (RC17/027 and RC18/374) to MA. BB was funded by a PhD fellowship from Spanish MCIU FPU16/02139. PD-C was supported by a Ramón y Cajal contract from the MICINN, Call 2019.Peer reviewe

<i>Galleria mellonella</i> Infection Model Demonstrates High Lethality of ST69 and ST127 Uropathogenic <i>E. coli - Table 1 </i>

<p>Statistical analysis indicates the significant difference in carriage of virulence factors (based on a PCR survey) and lethal effects (Low LD₅₀) with larvae inoculated with ST69 and ST127 strains.</p

Correlation analysis between the five UPEC sequences types: (A) Low LD₅₀ shows significant lethal effects with larvae inoculated with ST69 and ST127 strains.

<p>(B) ST127 shows high virulence capacity compared to that of other STs and ST131 shows relatively low virulence capacity.</p

Virulence profile of ST127 strains based on PCR detection of 29 uropathogen associated virulence factors.

<p>EC18 (avirulent strain) shows a similar profile compared to other ST127 virulent strains. Black blocks represent positive PCR results and strain numbers are in the left hand column.</p