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

Eiman Sarkhoo,Elke Mueller,Ralf Ehricht,Edet E Udo,Samar S Boswihi,Stefan Monecke

doi:10.3389/fmicb.2021.658772

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex 361 (CC361-MRSA) is rare among patients’ populations globally. However, CC361-MRSA has been isolated with an increasing trend among patients in Kuwait hospitals since 2010. This study investigated the molecular characteristics of CC361-MRSA isolated from patients in Kuwait hospitals in 2016–2018 to understand their genetic relatedness and virulence determinants. Of 5,223 MRSA isolates investigated by DNA microarray, 182 (3.4%) isolates obtained in 2016 (N = 55), 2017 (N = 56), and 2018 (N = 71) were identified as CC361-MRSA. The CC361-MRSA isolates were analyzed further using antibiogram, spa typing and multi locus sequence typing (MLST). Most of the isolates were resistant to fusidic acid (64.8%), kanamycin (43.4%), erythromycin (36.3%), and clindamycin (14.3%) encoded by fusC, aphA3, and erm(B)/erm(C) respectively. Nine isolates (4.9%) were resistant to linezolid mediated by cfr. The isolates belonged to 22 spa types with t3841 (N = 113), t315 (N = 16), t1309 (N = 14), and t3175 (N = 5) constituting 81.3% of the spa types, four genotypes (strain types), CC361-MRSA-[V/VT + fus] (N = 112), CC361-MRSA-IV, WA MRSA-29 (N = 36), CC361-MRSA-V, WA MRSA-70/110 (N = 33) and CC361-MRSA-[V + fus] variant (N = 1). MLST conducted on 69 representative isolates yielded two sequence types: ST361 (11/69) and ST672 (58/69). All CC361-MRSA isolates were positive for cap8, agr1, and the enterotoxin egc gene cluster (seg, sei, selm, seln, selo, and selu). The tst1 was detected in 19 isolates. The immune evasion cluster (IEC) genes type B (scn, chp, and sak) and type E (scn and sak) were detected in 20 and 152 isolates, respectively. The CC361-MRSA circulating in Kuwait hospitals consisted of two closely related sequence types, ST361 and ST672 with ST672-MRSA [V/VT + fus] as the dominant genotype. The dissemination of these newly emerged clones and the emergence of linezolid resistance limits therapeutic options, as well as present significant challenges for the control of MRSA infections in Kuwait hospitals.

Highlights

Methicillin-resistant Staphylococcus aureus (MRSA) remains a major universal healthcare problem as it causes a wide range of infections including skin and soft tissue infections (SSTI), pneumonia, bacteremia, endocarditis, and osteomyelitis (McCaig et al, 2006; Hassoun et al, 2017)
We investigated CC361-MRSA isolated from patients in public hospitals in Kuwait from 1 January, 2016 to 31 December, 2018, using staphylococcal protein A typing, multi-locus sequence typing (MLST) and DNA microarray to determine their antibiotic resistance and virulence profiles, and genetic relatedness
DNA microarray analysis performed on the 5,223 isolates revealed that 182 (3.4%) isolates were identified as CC361-MRSA

Summary

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA) remains a major universal healthcare problem as it causes a wide range of infections including skin and soft tissue infections (SSTI), pneumonia, bacteremia, endocarditis, and osteomyelitis (McCaig et al, 2006; Hassoun et al, 2017). HA-MRSA are characteristically multi-resistant to antibiotics and carry SCCmec types I, II or III (Monecke et al, 2011). CA-MRSA are usually more susceptible to nonbeta-lactam antibiotics and carry SCCmec types IV, V, or VI (David and Daum, 2010). The Livestock-associated MRSA (LAMRSA) initially caused major problems in agriculture and were the leading cause of bovine mastitis (Fluit, 2012) but have become prominent among livestock, people associated with livestock and those with no previous contact with livestock (Graveland et al, 2011; Köck et al, 2013; Wagenaar et al, 2009; Boswihi et al, 2020a)

Methods

Results

Discussion

Conclusion