Genomic analysis of Staphylococcus aureus from the West African Dwarf (WAD) goat in Nigeria

Abstract

Background Staphylococcus aureus can colonize various host species, and human-animal interaction is a significant factor for cross-species transmission. However, data on S. aureus colonization in animals, particularly on ruminants in close contact with humans, is limited. The West African Dwarf (WAD) goat is among the earliest domesticated ruminant associated with rural dwellers and small-holder farmers in sub-Saharan Africa. This study aimed to investigate the population structure, antibiotic resistance, and virulence gene determinants of S. aureus from the WAD goat in Nigeria. Methods Nasal samples were obtained from the WAD goat in five markets in Osun State, South-West Nigeria. S. aureus was characterized by antibiotic susceptibility testing, detection of virulence determinants, spa typing, and multilocus sequence typing (MLST). Representative isolates were selected for whole-genome sequencing, biofilm, and cytotoxicity assay. Results Of the 726 nasal samples obtained from the WAD goat, 90 S. aureus (12.4%) were recovered. Overall, 86 isolates were methicillin-susceptible, and four were mecA-positive (i.e., methicillin-resistant S. aureus [MRSA]). A diverse S. aureus clonal population was observed (20 sequence types [STs] and 37 spa types), while 35% (13/37) and 40% (8/20) were new spa types and STs, respectively. Eleven MLST clonal complexes (CC) were identified (CC1, CC5, CC8, CC15, CC30, CC45, CC97, CC121, CC133, CC152, CC522). The MRSA isolates were designated as t127-ST852-CC1-SCCmec type VII, t4690-ST152-CC152-SCCmec type Vc, and t8821-ST152-CC152-SCCmec type Vc. Phylogenetic analysis revealed that 60% (54/90) of all isolates were associated with ruminant lineages (i.e., CC133, CC522). Panton-Valentine Leukocidin (PVL)-positive S. aureus was identified in CC1, CC30, CC121, and CC152. For the CC522 isolates, we illustrate their pathogenic potential by the detection of the toxic shock syndrome gene and hemolysins, as well as their strong cytotoxicity and ability to form biofilms. Conclusions This is the first detailed investigation on the genomic content of S. aureus from the WAD goat in Nigeria. The S. aureus population of the WAD goat consists mainly of ruminant-associated lineages (e.g., CC133, CC522), interspersed with human-associated clones, including PVL-positive MRSA CC1 and CC152.

A 6-Year Update on the Diversity of Methicillin-Resistant Staphylococcus aureus Clones in Africa: A Systematic Review

“…This observation supports the evidence of multiple introductions among MSSA isolates in sub-Saharan Africa as the basis for the evolution of this clone ( Baig et al, 2020 ). Recent studies have also reported CC152-MRSA from humans ( Egyir et al, 2020 , 2021 ) and animals ( Shittu et al, 2021 ), including fomites ( Shittu et al, 2020b ) in Africa. The emergence of PVL-positive CC152-MRSA is of public health concern.…”

Sensitivity of Strains of Meticillin Resistant Staphylococcus aureus (MRSA), Isolated from Bacterial Infections in the District of Abidjan

“…This rate is higher than those obtained previously (25%) by Guessennd [15]. In addition, similar studies carried out in 2012 in some African countries such as Morocco and Tunisia revealed 18.5% and 40.5% resistance to cefoxitin, respectively [16]. On the other hand, higher rates were observed in Senegal with 72% in 2012 [17].…”

Colonization of Extramammary Sites with Mastitis-Associated S. aureus Strains in Dairy Goats

“…Several studies identified t1236 in IMI cases in cattle [33][34][35][36][37]. The t1236 spa genotype is associated with CC97, frequently found in mastitis in cattle and harbors a high frequency of methicillin-resistant strains [38][39][40][41] In goat, sheep and deer, strains from CC97 have been isolated from the nares [30,[42][43][44][45][46].…”