Clonal diversity and spatial dissemination of multi-antibiotics resistant Staphylococcus aureus pathotypes in Southwest Nigeria

Abstract

Spread of genetically diverse Staphylococcus aureus characterized with multi-antibiotic resistance and regulated by high level agr functionalities in several communities in southwest Nigeria was investigated and evaluated for infection control. Staphylococcus aureus pathotypes recovered from 256 cases including purulent pus from skin infections, soft tissue aspirates, wounds, otorrhea, eye, throat and endocervical infections were assayed for biofilm and antibiogram. Further genotyped with micro-array, mapped for geospatial distribution and evaluated for clonal diversity and functional accessory gene regulators (agr). Significant Staphylococci infection among the ages (OR:0.021, CI:0.545–1.914) and female gender with prevalence rate of MSSA (53.0%) and MRSA (1.5%) (OR:1.021, CI:0.374–1.785) were observed. More than 52.5% resistance rates to tetracycline and amoxicillin with significant median resistance were observed in all the infection cases (p = 0.001). Resistance rate of 78.8% at MIC50 32μg/ml and MIC90 128μg/ml to amoxicillin-clavulanate, and more than 40% resistance to ceftazidime, ciprofloxacin and tetracycline of MIC90 and MIC50 at 32 μg/ml were observed. Strains with multi-antibiotic resistance index above 0.83, high beta-lactamase and strong biofilm clustered into separate phylo-group. Heterogeneous t442 (wound and pus), t657 (wound), t091 (ear) and t657 (ear and wound) revealed high phylogenetic diversity. Only 4.6% pvl+ MSSA-CC1 agrI, pvl+ MSSA-CC5 (13.6%) and pvl+ MRSA-CC7 agrII (4.6%), expressed enterotoxin, leukocidins, proteases and resistance gene determinants. Livestock clonal types clustered with identified community-associated strains. Clonal dissemination of resistant pvl+ MSSA-CC1 and MRSA-CC5 encoding agr were predominant in several peri-urban communities where adequate geno-surveillance, population-target antimicrobial stewardship, extensive community structured infection control programs are needed to prevent further focal dissemination.

Antibacterial activities of plant leaf extracts against multi-antibiotic resistant Staphylococcus aureus associated with skin and soft tissue infections

“…Staphylococcus aureus infection of the furuncles, carbuncles, skin abscesses, and wounds are common skin and soft tissue infections (SSTIs) [ 3 ], which usually begin with minor boils and may progress to severe disease conditions associated with subcutaneous tissues, muscle, bones and bloodstream. The study reveals a significant rate of S. aureus infectivity in all age groups due to its contagious potential and transmission through skin contact, particularly with animals [ 19 , 35 ], which is frequently mediated by several adhesins [ 19 ]. Biofilm is a major component involved in S. aureus invasion.…”

“…Ethical permission from the Health Research Ethics Committees with protocol approval (FMCA/470/HREC/09/2017; NHREC/08/10–2015) was obtained. Each isolate was phenotypically characterized on mannitol salt and Baird-Parker agars and further Gram-stained and biotyped using API as previously described [ 19 ].…”

“…Zones of inhibitions were measured after aerobic incubation at 37 °C for 24 h and interpreted according to CLSI guidelines [ 23 ]. The multi-antibiotic resistance index (MARI) was determined [ 19 ], in which the number of antibiotics an isolate is resistant to is divided by the total number of antibiotics used. Resistance to at least one agent in three or more antimicrobial classes was defined as multidrug-resistant (MDR) and non-MDR as susceptibility to all antibiotics [ 24 ].…”

Emerging vancomycin-non susceptible coagulase negative Staphylococci associated with skin and soft tissue infections

“…The observable cluster of VNS- S sciuri lacking pvl , demonstrating high level heterogenous antibiotic resistance from peri-urban and rural communities, is a pending threat to public health [ 4 , 14 ]. This further suggests a stemming spread of VNS-CoNS infection of soft tissue, bloodstream and traumatized wounds.…”

“…The selection of patients with staphylococcal infection was based on the assessment of the physicians and the Ethical approval for the study was obtained (FMCA/470/HREC/09/2017). Suspected staphylococci colonies from 7% sheep blood agar culture, were phenotypically characterized on Baird-Parker medium, Mannitol salt agar (MSA) and MSA supplemented with Cefoxitin (4 µl/g) as previously described [ 14 ]. Typical colonies were further tested for hemolytic activity and coagulase production [ 15 ] and further biotyped with Analytical Profile Index (API).…”