Genotyping of methicillin resistant Staphylococcus aureus from the United Arab Emirates.

Reports from Arabian Gulf countries have demonstrated emergence of novel methicillin resistant Staphylococcus aureus (MRSA) strains. To address the lack of data from the United Arab Emirates (UAE), genetic characterisation of MRSA identified between December 2017 and August 2019 was conducted using DNA microarray-based assays. The 625 MRSA isolates studied were grouped into 23 clonal complexes (CCs) and assigned to 103 strains. CC5, CC6, CC22 and CC30 represented 54.2% (n/N = 339/625) of isolates with other common CCs being CC1, CC8, CC772, CC361, CC80, CC88. Emergence of CC398 MRSA, CC5-MRSA-IV Sri Lanka Clone and ST5/ST225-MRSA-II, Rhine-Hesse EMRSA/New York-Japan Clone in our setting was detected. Variants of pandemic CC8-MRSA-[IVa + ACME I] (PVL+) USA300 were detected and majority of CC772 strains were CC772-MRSA-V (PVL+), "Bengal- Bay Clone". Novel MRSA strains identified include CC5-MRSA-V (edinA+), CC5-MRSA-[VT + fusC], CC5-MRSA-IVa (tst1+), CC5-MRSA-[V/VT + cas + fusC + ccrA/B-1], CC8-MRSA-V/VT, CC22-MRSA-[IV + fusC + ccrAA/(C)], CC45-MRSA-[IV + fusC + tir], CC80-MRSA-IVa, CC121-MRSA-V/VT, CC152-MRSA-[V + fusC] (PVL+). Although several strains harboured SCC-borne fusidic acid resistance (fusC) (n = 181), erythromycin/clindamycin resistance (ermC) (n = 132) and gentamicin resistance (aacA-aphD) (n = 179) genes, none harboured vancomycin resistance genes while mupirocin resistance gene mupR (n = 2) and cfr gene (n = 1) were rare. An extensive MRSA repertoire including CCs previously unreported in the region and novel strains which probably arose locally suggest an evolving MRSA landscape.

Characterisation of a novel SCCmec VI element harbouring fusC in an emerging Staphylococcus aureus strain from the Arabian Gulf region.

Fusidic acid is a steroid antibiotic known since the 1960s. It is frequently used in topical preparations, i.e., ointments, for the treatment of skin and soft tissue infections caused by Staphylococcus aureus. There is an increasing number of methicillin-resistant S. aureus (MRSA) strains that harbour plasmid-borne fusB/far1 or fusC that is localised on SCC elements. In this study we examined a series of related CC30-MRSA isolates from the Arabian Gulf countries that presented with SCCmec elements and fusC, including a variant that-to the best of our knowledge-has not yet formally been described. It consisted of a class B mec complex and ccrA/B-4 genes. The fusidic acid resistance gene fusC was present, but contrary to the previously sequenced element of HDE288, it was not accompanied by tirS. This element was identified in CC30 MRSA from Kuwait, Saudi Arabia and the United Arab Emirates that usually also harbour the Panton-Valentin leukocidin (PVL) genes. It was also identified in CC8 and ST834 isolates. In addition, further CC30 MRSA strains with other SCCmec VI elements harbouring fusC were found to circulate in the Arabian Gulf region. It can be assumed that MRSA strains with SCCmec elements that include fusC have a selective advantage in both hospital and community settings warranting a review of the use of topical antibiotics and indicating the necessity of reducing over-the-counter sale of antibiotics, including fusidic acid, without prescription.

Role of outer membrane permeability, efflux mechanism, and carbapenemases in carbapenem-nonsusceptible Pseudomonas aeruginosa from Dubai hospitals: Results of the first cross-sectional survey.

OBJECTIVES: Carbapenem resistance in Pseudomonas aeruginosa is growing and results from variable mechanisms. The objectives of the current study were to investigate mechanisms of carbapenem resistance and genetic relatedness of P. aeruginosa isolates recovered in Dubai hospitals. METHODS: From June 2015 through June 2016, carbapenem-nonsusceptible P. aeruginosa were collected from 4 hospitals in Dubai, and subjected to antimicrobial susceptibility testing, molecular investigation of carbapenemases by PCR-sequencing, analysis of outer membrane porin OprD2 and multidrug efflux channel MexAB-OprM levels by qPCR, and fingerprinting by ERIC-PCR. RESULTS: Out of 1969 P. aeruginosa isolated during the study period, 471 (23.9%) showed reduced carbapenem susceptibility. Of these, 37 were analyzed and 32% of them produced VIM-type metallo-ß-lactamases, including VIM-2, VIM-30, VIM-31, and VIM-42, while GES-5 and GES-9 co-existed with VIM in 5.4% of isolates. Outer membrane impermeability was observed in 73% of isolates and 75.6% displayed overproduced MexAB-OprM. ERIC-PCR revealed one large clone including most carbapenemase-producing isolates indicating clonal dissemination. CONCLUSION: This is the first study on carbapenem-nonsusceptible P. aeruginosa from Dubai, incriminating VIM production as well as outer membrane permeability and efflux systems as resistance mechanisms. Further studies on carbapenem-nonsusceptible P. aeruginosa in Dubai are warranted for containment of such health hazard.

Clonal emergence of Klebsiella pneumoniae ST14 co-producing OXA-48-type and NDM carbapenemases with high rate of colistin resistance in Dubai, United Arab Emirates.

Few studies have addressed the molecular epidemiology of carbapenem-resistant Enterobacteriaceae (CRE) isolates in the Arabian Peninsula, and such investigations have been missing from Dubai, a major economical, tourism and medical centre of the region. The antibiotic susceptibility, the carbapenemase type produced, and the clonality of 89 CRE strains isolated in five major Dubai hospitals in June 2015 to June 2016 were determined. Thirty-three percent of the collection of 70 Klebsiella pneumoniae, 13 Escherichia coli and 6 other Enterobacteriaceae were extremely drug resistant, 27% were resistant to colistin, and 4.5% (4 K. pneumoniae isolates) were resistant to all antibiotics tested. The colistin resistance rate in K. pneumoniae was 31.4%. None of the isolates carried mobile colistin resistance genes. Seventy-seven isolates produced carbapenemase: 53.3% OXA-48-like, 24.7% NDM and 22.1% both OXA-48-like and NDM, respectively. Pulsed-field gel electrophoresis clustered 50% of K. pneumoniae into a 35-membered group, which showed significant association with double carbapenemase production, with extreme drug resistance, and with being isolated from Emirati patients. Members of the cluster belonged to sequence type ST14. The rate of colistin resistance in K. pneumoniae ST14 was 37.1% vs. 27.1% of K. pneumoniae isolates outside of the cluster. Two of the panresistant K. pneumoniae isolates also belonged to ST14, whereas the other two were ST15 and ST231, respectively. In conclusion, beyond the overall high colistin resistance rate in CRE, the emergence of a highly resistant clone of K. pneumoniae ST14 in all Dubai hospitals investigated is a serious problem requiring immediate attention.