scholarly journals Antibiotic resistance and clonal diversity of invasive Staphylococcus aureus in the rural Ashanti Region, Ghana

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Denise Dekker ◽  
Manuel Wolters ◽  
Eva Mertens ◽  
Kennedy Gyau Boahen ◽  
Ralf Krumkamp ◽  
...  
2021 ◽  
Author(s):  
Crystal Ngofi Zumbi ◽  
Vivian Etsiapa Boamah ◽  
Yaw Duah Boakye ◽  
Hayford Odoi ◽  
Christian Agyare

Abstract Background: Antibiotic resistance in bacteria has long been recognized as a major health problem occurring worldwide. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) remains a global health problem. MRSA is reported as one of the leading pathogens involved in increased rates of morbidity and mortality amongst patients in Ghana. This study determined the prevalence and resistance mechanisms of MRSA isolated from patients in selected hospitals in the Ashanti Region of Ghana. Antibiograms of the isolates were determined using the Kirby-Bauer disk diffusion method. Antibiotic resistance genes (mecA and mecC) were detected and efflux pump activity assessed using polymerase chain reaction (PCR) and microbroth dilution methods, respectively. Results: Out of 626 samples obtained from patients, S. aureus was identified in 68, representing 10.9%. Multidrug resistance (MDR) was observed in 46 (67.6%) of the S. aureus isolates of which 28 (60.9%) were Methicillin Resistant Staphylococcus aureus (MRSA). The MRSA isolates showed higher susceptibility to trimethoprim-sulfamethoxazole (50%) and higher resistance to oxacillin and cefoxitin (100%). mecA gene was identified in 9 (32.1%) of the MRSA isolates whereas mecC gene was absent in all the isolates. The isolates did not exhibit any multiple efflux pump activities. Conclusion: The prevalence of MDR-MRSA in S. aureus infections at healthcare facilities in the Ashanti region was found to be high. The presence of the mecA gene was identified as a possible mechanism responsible for resistance in the MRSA isolates.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247013
Author(s):  
Akinniyi Paul Akinduti ◽  
Joshua Adekunle Osiyemi ◽  
Temitope Temitayo Banjo ◽  
Oluwaseun Ejilude ◽  
Maged El-Ashker ◽  
...  

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.


2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.


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