Molecular Epidemiology and Antimicrobial Susceptibility of Clinical Staphylococcus aureus from Healthcare Institutions in Ghana

Abstract

The objective of this study was to determine the antimicrobial susceptibility patterns and clonal diversity of clinical Staphylococcus aureus isolates from Ghana. A total of 308 S. aureus isolates from six healthcare institutions located across Northern, Central and Southern Ghana were characterized by antibiotyping, spa typing and PCR detection of Panton Valentine leukocin (PVL) genes. Methicillin-resistant S. aureus (MRSA) were confirmed by PCR detection of mecA gene and further characterized by SCCmec and multi-locus sequence typing (MLST). The prevalence of antimicrobial resistance was below 5% for all agents tested except for penicillin (97%), tetracycline (42%) and erythromycin (6%). Ninety-one spa types were found, with t355 (ST152, 19%), t084 (ST15, 12%) and t314 (ST121, 6%) being the most frequent types. Based on established associations between spa and MLST types, isolates were assigned to 16 clonal complexes (CCs): CC152 (n = 78), CC15 (n = 57), CC121 (n = 39), CC8 (n = 36), CC5 (n = 33), CC1 (n = 29), CC45 (n = 9), CC88 (n = 8), CC30 (n = 4), CC9 (n = 3), CC25 (n = 2), CC97 (n = 2) CC20 (n = 2), CC707 (n = 2), CC7 (n = 3) and CC522 (n = 1). Most isolates (60%) were PVL-positive, especially those belonging to ST152, ST121, ST5, ST15, ST1, ST8, and ST88. Nine (3%) isolates were MRSA belonging to seven distinct clones: ST88-IV (n = 2), ST250-I (n = 2), ST8-IV (n = 1), ST72-V (n = 1), ST789-IV (n = 1), ST2021-V (n = 1), and ST239-III (n = 1). The study confirmed a high frequency of PVL-positive S. aureus in Africa, low prevalence of antimicrobial resistance and high diversity of MRSA lineages in Ghana compared to developed countries and other African countries. The detection of known pandemic MRSA clones in the absence of routine MRSA identification in most Ghanaian clinical microbiology laboratories calls for capacity building to strengthen surveillance and prevent spread of these clones.

Rapid Detection of Panton-Valentine Leukocidin (PVL) Gene from Staphylococcus aureus Clinical Isolates

“…Also Gülmez et al, 2012 found MRSA to be 97 (34%) out of 285 S. aureus isolates. The observed MRSA prevalence among clinical isolates in Ghana is similar to those reported in European countries with low MRSA prevalence, such as the Scandinavian countries and The Netherlands (Egyir et al, 2014). …”

“…The prevalence of MRSA (3%) was lower than those reported in other African countries such as Nigeria (20%), Algeria (45%) and in a multicenter study (15%) involving five major African towns. Egyir et al, 2014 attributed the low MRSA frequency reported in their study to the low consumption of antimicrobial agents such as fluoroquinolones and third generation cephalosporins in Ghana, because they are expensive and are usually prescribed for acute infections. Usage of the aforementioned antimicrobial agents has been shown to correlate with an increase in MRSA prevalence (Egyir et al, 2014).…”

“…Egyir et al, 2014 attributed the low MRSA frequency reported in their study to the low consumption of antimicrobial agents such as fluoroquinolones and third generation cephalosporins in Ghana, because they are expensive and are usually prescribed for acute infections. Usage of the aforementioned antimicrobial agents has been shown to correlate with an increase in MRSA prevalence (Egyir et al, 2014). In another western country WD et al, 2010 found that CA-MRSA accounted for 4% (14) of S. aureus isolates.…”

“…Levels reported elsewhere differed substantially ranging from 22% -65%. However, there are evidences that the prevalence of MRSA has increased worldwide (Kheder et al, 2012).On the other hand a study made by Egyir et al, 2014 in Ghana on 903 staphylococci collected, 308 (34%) were identified as S. aureus and 595 (66%) as coagulase negative staphylococci. MRSA and MSSA isolates formed nearly (3%), (97%) respectively.…”

Characterization of Staphylococcus aureus from Human Immunodeficiency Virus (HIV) patients in Accra, Ghana

“…A recent study showed S. aureus and MRSA carriage prevalence of 14% and 10% among inpatients (not diagnosed with HIV) at Korle Bu teaching hospital in Ghana [8]. In this same geographic setting, spa type t355 and t084 together with high prevalence of PVL (21-60%) were predominantly detected [8,9]. There is however, no information on S. aureus carriage strains among HIV-infected patients in Ghana.…”