Human mecC-Carrying MRSA: Clinical Implications and Risk Factors

Abstract

A new methicillin resistance gene, named mecC, was first described in 2011 in both humans and animals. Since then, this gene has been detected in different production and free-living animals and as an agent causing infections in some humans. The possible impact that these isolates can have in clinical settings remains unknown. The current available information about mecC-carrying methicillin resistant S. aureus (MRSA) isolates obtained from human samples was analyzed in order to establish its possible clinical implications as well as to determine the infection types associated with this resistance mechanism, the characteristics of these mecC-carrying isolates, their possible relation with animals and the presence of other risk factors. Until now, most human mecC-MRSA infections have been reported in Europe and mecC-MRSA isolates have been identified belonging to a small number of clonal complexes. Although the prevalence of mecC-MRSA human infections is very low and isolates usually contain few resistance (except for beta-lactams) and virulence genes, first isolates harboring important virulence genes or that are resistant to non-beta lactams have already been described. Moreover, severe and even fatal human infection cases have been detected. mecC-carrying MRSA should be taken into consideration in hospital, veterinary and food safety laboratories and in prevention strategies in order to avoid possible emerging health problems.

Anandamide alters the membrane properties, halts the cell division and prevents drug efflux in multidrug resistant Staphylococcus aureus

“…But also here, bacteria emerge that have acquired resistance to these antibiotics through mutations in pbp2 , pbp4 and gdpP 11 . Another cause of β-lactam resistance is the expression of mecC that encodes for a PBP2a/2′ variant 12 .…”

Genomic Analysis of Staphylococcus aureus of the Lineage CC130, Including mecC-Carrying MRSA and MSSA Isolates Recovered of Animal, Human, and Environmental Origins

“…Since then, this lineage has been detected in diverse hosts in many European countries, with cattle and wildlife (including free grazing domesticated animals) being the most common hosts ( Zarazaga et al, 2018 ). The prevalence of mecC -MRSA in people seems to be low ( Paterson et al, 2014a , b ; Lozano et al, 2020 ), however, the zoonotic transmission from livestock to people has been reported ( Harrison et al, 2013 ), as well as its ability to cause disease ( Petersen et al, 2013 ). This mecC -MRSA-CC130 lineage seems to be susceptible to many non-β-lactam agents and lacks major human virulence factors ( Cuny et al, 2011 ; Monecke et al, 2013 ; Paterson et al, 2014a ).…”

“…This IEC system is found in seven different configurations (types A–G) depending on the combination of five genes ( scn , chp , sak , sea / sep ); the scn gene (encodes a staphylococcal complement inhibitor) is included in all IEC types, and is often used as a marker of IEC-positive isolates, and is functionally essential ( van Wamel et al, 2006 ). None of the mecC -MRSA reported strains harbored the scn gene (essential for the IEC system) ( Lozano et al, 2020 ), with the exception of a few isolates belonging to ST1945, ST1581, and ST1583 previously described by our group from wildlife and extensively farmed domestic animals ( Gómez et al, 2014 , 2015 ; Ruiz-Ripa et al, 2019 ) and one ST1945 MRSA strain from a human sample ( Harrison et al, 2017 ); it is worth noting that all these IEC-positive isolates were of type-E (carrying the scn and sak genes).…”

Nisin activity against methicillin-resistant and methicillin-sensitive Staphylococcus aureus and risk of resistance acquisition

“…This phenomenon implies a diminishing existence of effective antimicrobial agents to treat infections caused by these bacteria (Magiorakos et al, 2012;Lin et al, 2017). Among antibiotic-resistant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) is spreading worldwide in both hospital (HA-MRSA) and community (CA-MRSA) settings, including livestock animals (LA-MRSA) (Castro et al, 2017;Lakhundi & Zhang, 2018;Lozano et al, 2020;Togneri et al, 2017). Infections caused by MRSA constitute one of three major infectious diseases, threatening human health (Center for Disease Control and Prevention, 2015;Lozano et al, 2020;Togneri et al, 2017).…”