Methicillin-resistant Staphylococcus aureus with mecC: a description of 45 human cases in southern Sweden

Abstract

In 2011, a novel mecA gene homologue, mecC, was reported in isolates from both humans and dairy cattle. The epidemiology of mecC methicillin-resistant Staphylococcus aureus (MRSA) in humans is not yet well known. In this retrospective study, we present the epidemiology of human clinical cases with mecC MRSA detected in the southern part of Sweden during the period 2005-2014. A total of 45 patients with an isolate positive for mecC MRSA were included in the study. Twenty-six isolates were found before 2012 and were retrospectively tested for mecC. Nineteen isolates were detected in 2012-2014 through routine testing. Culture results, resistance patterns, Panton-Valentine leukocidin (PVL) genes, and spa types were collected from the Clinical Microbiology Laboratory. Epidemiological data were received from the database at the Regional Centre for Communicable Disease Control and the patient's medical files. The majority of the patients with mecC MRSA were of Swedish origin, had underlying diseases, and lived in rural areas. The median age was 60 years. Of the mecC MRSA, 76 % belonged to spa types t373 and t843. The median minimum inhibitory concentration (MIC) value for oxacillin was 16 mg/L (1-64 mg/L) and only one isolate was resistant to other classes of antibiotics. The most common type of infection was skin and soft tissue infections, most often in an existing skin lesion. The patients with mecC MRSA were colonized for a short time and gave rise to few secondary cases. mecC MRSA in our region appears to have a domestic origin and mainly affects patients with underlying diseases or patients with an existing skin lesion. Our data indicate that it could be a poor colonizer.

Evaluation of the Role Of bla Genes in Beta Lactam and Methicillin Resistant Staphylococcus aureus

“…In our study the absence of mecA and blaZ genes was detected in 2% of the isolates. hence, the hypothesis that mecA absence could be compensated by mecC gene, a homologue of mecA gene within newly emerging and recently recognized cassette chromosome for methicillin resistance may be accepted (Paterson et al, 2014 andLindgren et al, 2016).…”

Molecular Epidemiology of Staphylococcus aureus Lineages in Wild Animals in Europe: A Review

“…Although the detection of mecC-MRSA in humans is uncommon, spa-type t843 has been reported in humans and occasionally associated with zoonotic transmission [168,169]. spa-type t373 is one of the predominant types among mecC-MRSA strains isolated from humans, nevertheless, this spa-type has not been reported in mecC-MRSA from wildlife [168,170]. mecC-MRSA spa-types t978 and t3391 were reported in two different studies with hedgehogs, both studies reported a high frequency of t978, t3391 and t843 among these animals.…”

Human mecC-Carrying MRSA: Clinical Implications and Risk Factors

“…A total of 61 human case reports associated with mecC -MRSA isolates has been described ( Table 3 ) [ 17 , 36 , 37 , 45 , 76 , 77 , 78 , 79 , 80 , 81 ]. Although mecC -positive isolates have been identified in Asia, Europe, and Oceania [ 21 , 82 , 83 ] in different hosts, all human case reports were described in European countries ( Table 3 ).…”