Insights into Nasal Carriage of Staphylococcus aureus in an Urban and a Rural Community in Ghana

Abstract

The epidemiology of Staphylococcus aureus in the community in Ghana was never investigated prior to this study. The aims of the study were: i) to assess prevalence of nasal S. aureus carriage in Ghanaian people living in an urban and a rural area, and ii) to identify phenotypic and genotypic traits of strains isolated from the two communities. Nasal swabs were collected from healthy individuals living in an urban community situated in the suburb of the capital city, Accra (n = 353) and in a rural community situated in the Dangme-West district (n = 234). The overall prevalence of nasal carriage was 21% with a significantly higher prevalence in the urban (28%) than in the rural community (11%) (p<0.0001). The levels of antimicrobial resistance were generally low (<5%) except for penicillin (91%) and tetracycline (25%). The only two (0.3%) MRSA carriers were individuals living in the urban area and had been exposed to hospitals within the last 12 months prior to sampling. Resistance to tetracycline (p = 0.0009) and presence of Panton-Valentine leukocidin (PVL) gene (p = 0.02) were significantly higher among isolates from the rural community compared to isolates from the urban community. Eleven MLST clonal complexes (CC) were detected based on spa typing of the 124 S. aureus isolates from the two communities: CC8 (n = 36), CC152 (n = 21), CC45 (n = 21), CC15 (n = 18), CC121 (n = 6), CC97 (n = 6), CC30 (n = 5), CC5 (n = 5), CC508 (n = 4), CC9 (n = 1), and CC707 (n = 1). CC8 and CC45 were less frequent in the rural area than in the urban area (p = 0.02). These results reveal remarkable differences regarding carriage prevalence, tetracycline resistance, PVL content and clonal distribution of S. aureus in the two study populations. Future research may be required to establish whether such differences in nasal S. aureus carriage are linked to socio-economic differences between urban and rural communities in this African country.

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

“…Table 2 shows the molecular characteristics of all S. aureus isolates in the study. PVL-postive isolates (3/10, 30%) belonged to CC15 (n = 1) and CC152 (n=2), similar to the observation in earlier studies in Ghana [8,9,13].…”

“…The finding of spa type t084 in multiple patients was anticipated as this lineage was common in earlier hospital and community studies in Ghana [8,9,13]. Surprisingly, spa type t355, the frequent clone detected among clinical and non clinical isolates in recent studies in Ghana [8,9,13] was not found among this group of patients suggesting differences in S. aureus clone distribution with patient groups in this country. Table 2 shows the molecular characteristics of all S. aureus isolates in the study.…”

“…The ten S. aureus isolates were genetically diverse with t084 (n = 3) and t10828 (n = 2) as frequent spa types contrary to the predominant spa types (t064 and t3772) reported among HIV-infected patients in Nigeria [2]. The finding of spa type t084 in multiple patients was anticipated as this lineage was common in earlier hospital and community studies in Ghana [8,9,13]. Surprisingly, spa type t355, the frequent clone detected among clinical and non clinical isolates in recent studies in Ghana [8,9,13] was not found among this group of patients suggesting differences in S. aureus clone distribution with patient groups in this country.…”

spa typing and antimicrobial resistance of Staphylococcus aureus from healthy humans, pigs and dogs in Tanzania

“…Resistances to ampicillin and tetracycline have been reported worldwide [5], including referral hospitals in Tanzania [31,32] and community settings in other African countries such as Ghana [33]. Resistance to gentamicin was reported in 41.5% of human clinical isolates derived from a hospital in Tanzania [34] but it was low among human and animal isolates investigated by our study.…”

Livestock-Associated MRSA and Its Current Evolution

“…It was determined that the human strains originated from a bovine to human host jump believed to have occurred approximately 40 years ago and subsequently acquired methicillin resistance [81]. MSSA CC97 strains are still circulating in humans [82,83].…”