<p>Emergence of novel methicillin-resistant <em>Staphylococcus aureus</em> strains in a tertiary care facility in Riyadh, Saudi Arabia</p>

Abstract

Purpose There is a need for continuous surveillance of methicillin-resistant Staphylococcus aureus (MRSA) to identify emergence of new strains. We hypothesize that MRSA strains are evolving with ongoing acquisition of SCC mec elements. This study was carried out to evaluate the evolution of MRSA at a tertiary care facility in Saudi Arabia. Methods MRSA isolates associated with invasive clinical infection, which were identified in 2017 at the microbiology laboratory, King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia, were studied. The molecular characterization of isolates was carried out using StaphyType DNA microarray (Alere Technologies GmbH/Abbott, Jena, Germany). Results The 125 MRSA isolates studied belonged to 18 clonal complexes (CC) which were distributed into 32 strain assignments. The predominant CC were CC5 (n=30), CC6 (n=17), CC80 (n=13), CC22 (n=12), CC361 (n=12). The findings demonstrated the first identification of CC152, CC361 and CC1153 MRSA as well as ST5-MRSA-[I+fus], “Geraldine Clone”, CC6-MRSA-IV (PVL+) and CC88-MRSA-V (PVL+), WA MRSA-117 in Saudi Arabia. Four novel variants were identified: CC5-MRSA-[VI+fus+tirS], CC22-MRSA-[V/VT+fus](PVL+), CC152-MRSA-[V+fus](PVL+) and CC361-MRSA-[VT+fus]. Fifty-four isolates (n/N=54/125; 43.2%) including the novel strains carried the Q6GD50 SCC fusC gene while the Panton-Valentine leukocidin genes were present in 30.4% (n/N=38/125). Conclusion The findings demonstrate an expanding MRSA repertoire in our setting including emergence of previously unreported clonal complexes and novel strains. The high carriage of fusC gene suggests a role for fusidic acid misuse in driving the evolution of the MRSA genome and underscores the need for increased monitoring of antibiotic use.

The Dissemination and Molecular Characterization of Clonal Complex 361 (CC361) Methicillin-Resistant Staphylococcus aureus (MRSA) in Kuwait Hospitals

“…Despite the smaller numbers reported in Saudi Arabia (8 0f 12 isolates) (Senok et al, 2019) and the UAE (20 of 35 isolates) (Senok et al, 2020) compared to those in Kuwait, CC361-MRSA [V/VT + fus] isolates were also the most common strain type reported in these countries. Similarly, the second common genotype in this study, CC361-MRSA-IV, WA-MRSA 29, was also the second most common CC361-MRSA in the UAE blaZ, beta-lactamase gene; blaI, beta lactamase repressor (inhibitor); blaR, beta-lactamase regulatory protein; mecA, penicillin binding protein 2; erm(B) + erm(C), rRNA methyltransferase associated with macrolide/lincosamide resistance; linA, lincosaminide nucleotidyltransferase; msr(A), macrolide efflux pump; mph(C), macrolide phosphotransferase II; vatA, virginiamycin A acetyltransferase; vatB, acetyltransferase inactivating streptogramin A; vga(A), ABC transporter conferring resistance to streptogramin A; aacA-aphD, aminoglycoside adenyl-/phosphotransferase (gentamicin, tobramycin); aadD, aminoglycoside adenyltransferase (neomycin, kanamycin, and tobramycin); aphA3, aminoglycoside phosphotransferase (neomycin, kanamycin); dfrS1, dihydrofolate reductase mediating trimethoprim resistance; fusC + fusB (far1), fusidic acid resistance gene; tet(K), tetracycline efflux protein; Cfr, 23S rRNA methyltransferase; mupA, isoleucyl-tRNA synthetase; qacA, multidrug efflux protein A; qacC, multidrug efflux protein C; sat, streptothricin acetyltransferase; fosB, metallothiol transferase; ugpQ, glycerophosphoryl diester phosphodiesterase (associated with mecA); plsSCC (COL), plasmin-sensitive surface protein; delta_mecR, truncated signal transducer protein MecR1; Q9XB68-dcs, hypothetical protein from SCCmec elements; ccrC, cassette chromosome recombinase gene C; ccrB-2, cassette chromosome recombinase gene B-2; ccrA-2, cassette chromosome recombinase gene A-2; ccrA-3, cassette chromosome recombinase gene A-3; ccrAA, Putative protein homologue to cassette chromosome recombinase A genes.…”

“…Besides the diversity in spa types, the insolates in this study harbored different SCCmec types consisting of SCCmec types IV, V and V/VT that are usually associated with communityassociated genotypes. Apart from SCCmec V/VT, SCCmec types IV and V were also reported in CC361-MRSA from human patients in Western Australia (Monecke et al, 2011), Ireland (Kinnevey et al, 2014) and Bangladesh (Afroz et al, 2008), Abu Dhabi (Weber et al, 2010), Oman (Udo et al, 2014) and Saudi Arabia (Senok et al, 2019) and in animals in Nepal (Roberts et al, 2019) and Czech Republic (Tegegne et al, 2017). CC361 isolates were also reported to harbor SCCmec VIII in Australia where it is known as WA MRSA-28 (Nimmo and Coombs, 2008).…”

Genetic Polymorphism Drives Susceptibility Between Bacteria and Bacteriophages

“…With the emergence of antibiotic-resistant bacteria such as methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA), the treatment of bacterial infections through antibiotics has become increasingly problematic ( Sakoulas et al, 2005 ; Senok et al, 2019 ). As an alternative, phage therapy has attracted new interest for the treatment of antibiotic-resistant bacteria in recent years ( Levin and Bull, 2004 ; Lyon, 2017 ).…”

<p>Emergence of Methicillin-Resistant <em>Staphylococcus aureus</em> Belonging to Clonal Complex 15 (CC15-MRSA) in Kuwait Hospitals</p>

“…1,2 In addition, novel MRSA clones as well as variants of the established CA-MRSA clones continue to emerge. 12,13,15,18 The constant changes in the distribution of MRSA clones warrants regular surveillance of MRSA in local healthcare facilities to detect the newly emerging clones so as to institute effective control measures and prevent their transmission. 14,15 MRSA strains belonging to clonal complex 15 (CC15-MRSA) are rare in the literature with only small numbers reported in retail camel meat in Saudi Arabia 12 and in a small number of human patients in Saudi Arabia, 13,16 Iran 17,18 and Italy.…”

“…12,13,15,18 The constant changes in the distribution of MRSA clones warrants regular surveillance of MRSA in local healthcare facilities to detect the newly emerging clones so as to institute effective control measures and prevent their transmission. 14,15 MRSA strains belonging to clonal complex 15 (CC15-MRSA) are rare in the literature with only small numbers reported in retail camel meat in Saudi Arabia 12 and in a small number of human patients in Saudi Arabia, 13,16 Iran 17,18 and Italy. 19 Whole genome sequencing of four CC15-MRSA isolates cultured from human patients (N=2), and retail meat (N=2) in Saudi Arabia revealed that all four isolates belonged to the same sequence type, ST1535 (13-13-1-1-81-11-13), which is a single locus variant of ST15 and harbored a novel SCCmec V/SCCfus composite genetic element.…”