Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a serious global problem, with considerable impact on patients and substantial health care costs. This systematic review provides an overview on the clonal diversity of MRSA, as well as the prevalence of Panton-Valentine leukocidin (PVL)-positive MRSA in Africa. A search on the molecular characterization of MRSA in Africa was conducted by two authors using predefined terms. We screened for articles published in English and French through to October 2014 from five electronic databases. A total of 57 eligible studies were identified. Thirty-four reports from 15 countries provided adequate genotyping data. CC5 is the predominant clonal complex in the healthcare setting in Africa. The hospital-associated MRSA ST239/ST241-III [3A] was identified in nine African countries. This clone was also described with SCCmec type IV [2B] in Algeria and Nigeria, and type V [5C] in Niger. In Africa, the European ST80-IV [2B] clone was limited to Algeria, Egypt and Tunisia. The clonal types ST22-IV [2B], ST36-II [2A], and ST612-IV [2B] were only reported in South Africa. No clear distinctions were observed between MRSA responsible for hospital and community infections. The community clones ST8-IV [2B] and ST88-IV [2B] were reported both in the hospital and community settings in Angola, Cameroon, Gabon, Ghana, Madagascar, Nigeria, and São Tomé and Príncipe. The proportion of PVL-positive MRSA carriage and/or infections ranged from 0.3 to 100% in humans. A number of pandemic clones were identified in Africa. Moreover, some MRSA clones are limited to specific countries or regions. We strongly advocate for more surveillance studies on MRSA in Africa.
Highlights
Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern and is responsible for both hospital- and community-associated infections worldwide (De Kraker et al, 2011; CDC, 2013; Falagas et al, 2013; Garza-González and Dowzicky, 2013; Lee et al, 2013; Chen and Huang, 2014)
Characteristics of the Studies Included in the Systematic Review Most of the data analyzed were obtained from single center studies conducted mainly in five countries; Tunisia (n = 13), Nigeria (n = 9), South Africa (n = 7), Algeria (n = 5), and Egypt (n = 3) (Table 1)
Since ancient methicillin-susceptible S. aureus (MSSA) strains for this sequence type (ST) have not been reported (Enright et al, 2002), our observation suggests that acquisition of these staphylococcal cassette chromosome mec (SCCmec) types by MSSA is less likely, and points to the possible replacement of SCCmec type III with IV and V on the ST239/241 genome (Li et al, 2013)
Summary
Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern and is responsible for both hospital- and community-associated infections worldwide (De Kraker et al, 2011; CDC, 2013; Falagas et al, 2013; Garza-González and Dowzicky, 2013; Lee et al, 2013; Chen and Huang, 2014). SCCmec IV (21–24 kb) and V (27 kb) are shorter elements, generally susceptible to non-beta-lactam antibiotics, and linked with community MRSA (Chambers and Deleo, 2010). A variant mecA gene (named mecC) which is situated on an SCCmec XI element has been described (Shore et al, 2011). It has a higher relative affinity for oxacillin as compared with cefoxitin (Kim et al, 2012), and exhibits only 69% sequence similarity at the nucleotide level and 63% amino-acid identity to mecA/PBP2a (Paterson et al, 2014b). Based on whole genome sequencing, mutations of the endogenous penicillin-binding proteins (PBP) 1, 2, and 3 in mecA and mecC negative strains have been postulated as a possible alternative mechanism for beta-lactam resistance in MRSA (Ba et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
