scholarly journals Characterization of Toxin Gene Profiles and Antibiotic Resistance Genes of Methicillin Resistant Staphylococcus aureus Isolated from Ducks

2021 ◽  
Vol 9 (8) ◽  
Author(s):  
Mona A. A. AbdelRahman ◽  
Fatma Amer
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Resistance Genes ◽  
Toxin Gene ◽  
Methicillin Resistant ◽  
Gene Profiles

scholarly journals Susceptibility and molecular characterization of mec A- and mec B-positive community acquired methicillin-resistant Staphylococcus aureus isolates from students

2021 ◽  
Vol 18 (2) ◽  
pp. 155-171
Author(s):  
Patrick O. Olorunfemi ◽  
Ndidi C. Ngwuluka ◽  
Josiah A. Onaolapo ◽  
Yakubu K.E. Ibrahim
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Molecular Characterization ◽  
Resistance Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Public Health Importance ◽  
Methicillin Resistant ◽  
Spa Gene

Staphylococcus aureus is an organism of great public health importance. It is widely studied because it is virulent, causes life threatening disease and has ability to adapt to diverse environmental conditions and so develops resistance to antibiotics easily. As a result, there is a need for surveillance of its antibiotic resistance and resistance genes. The susceptibility and molecular characterization of methicillin resistant Staphylococcus aureus recovered from urine samples of healthy students were undertaken. Standard procedures were employed for isolation, identification, susceptibility, and polymerase chain reaction analyses. Out of 217 samples collected, 73 were confirmed Staphylococcus aureus. Most of the isolates were susceptible to ciprofloxacin and vancomycin followed by gentamicin and co-trimoxazole and least susceptible to penicillin, cefotaxime, ofloxacin and cefoxitin. Thirty-two (32) isolates were resistant to 5 antibiotics while 3 isolates were resistant to the 11 antibiotics used in this study. Sixteen phenotypically methicillin resistant isolates contained mecA gene while ten of the isolates also showed the presence of mecB gene. The characteristic Sa442 and nuc genes of Staphylococcus aureus and the presence of spa gene confirmed MRSA. Continous surveillance for antibiotic resistance and resistance genes is paramount at local, regional and national levels. Surveillance data will assist in implementing interventions. Keywords: Antibiotic resistance; Methicillin-resistant Staphylococcus aureus, mecA, mecB, CA-MRSA; Surveillance

scholarly journals Multi-drug resistance traits of methicillin-resistant Staphylococcus aureus and other Staphylococcal species from clinical and environmental sources

2019 ◽  
Vol 17 (6) ◽  
pp. 930-943 ◽  
Author(s):  
Adegboyega O. Oladipo ◽  
Oluwatosin G. Oladipo ◽  
Cornelius C. Bezuidenhout
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Animal Health ◽  
Antibiotic Resistance Genes ◽  
Multi Drug Resistance ◽  
Methicillin Resistant ◽  
Hospital Effluent ◽  
Resistance Traits

Abstract Multi-drug resistance traits of Staphylococcus species especially methicillin-resistant Staphylococcus aureus (MRSA) in the clinical settings are well established. Of environmental concern is hospital effluents discharging into wastewaters. This article investigated the prevalence and detection of antibiotic resistance genes in Staphylococcus species from clinical and environmental sources in Ile-Ife, Nigeria. Standard culture-based and molecular protocols were used. Seventy-six (27 clinical, 14 hospital effluent and 35 environmental) Staphylococcus isolates were recovered: 56.58% were coagulase-negative and 43.42% coagulase-positive (S. aureus). For the clinical isolates, 10, 6, 4, 4 and 1 were isolated from urine, skin, wounds, blood and pus, respectively. Isolates were resistant to methicillin and amoxycillin (91.7%), cloxacillin (88.0%), ciprofloxacin (84.0%), ofloxacin (83.3%), azithromycin (78.0%), ceftazidime (76.0%), gentamycin (75.0%), cefuroxime (75.0%) and erythromycin (72.0%). Nearly, all isolates (90.8%) had multiple antibiotic resistance (MAR) index >0.2. Overall MAR indices for Staphylococcus species isolated from the clinical, hospital effluent and environmental wastewaters were relatively similar (0.482; 0.500; 0.435). mecA, nuc and luk-pvl genes were detected in S. aureus, while mecA was detected in S. arlettae, S. sciuri, S. cohnii, S. epidermidis and S. saprophyticus. This study informs on the potential contamination of environmental waters downstream from hospitals and possible impacts that this could have on human and animal health.

scholarly journals Structural analysis of avibactam-mediated activation of the bla and mec divergons in methicillin-resistant Staphylococcus aureus

2020 ◽  
Vol 295 (32) ◽  
pp. 10870-10884 ◽  
Author(s):  
J. Andrew N. Alexander ◽  
Mariia Radaeva ◽  
Dustin T. King ◽  
Henry F. Chambers ◽  
Artem Cherkasov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Physiological Role ◽  
Antibiotic Resistance Genes ◽  
Binding Pocket ◽  
Methicillin Resistant ◽  
Mortality And Morbidity ◽  
Expression Of Genes ◽  
Genes Encoding

Methicillin-resistant Staphylococcus aureus (MRSA) infections cause significant mortality and morbidity globally. MRSA resistance to β-lactam antibiotics is mediated by two divergons that control levels of a β-lactamase, PC1, and a penicillin-binding protein poorly acylated by β-lactam antibiotics, PBP2a. Expression of genes encoding these proteins is controlled by two integral membrane proteins, BlaR1 and MecR1, which both have an extracellular β-lactam–binding sensor domain. Here, we solved the X-ray crystallographic structures of the BlaR1 and MecR1 sensor domains in complex with avibactam, a diazabicyclooctane β-lactamase inhibitor at 1.6–2.0 Å resolution. Additionally, we show that S. aureus SF8300, a clinically relevant strain from the USA300 clone of MRSA, responds to avibactam by up-regulating the expression of the blaZ and pbp2a antibiotic-resistance genes, encoding PC1 and PBP2a, respectively. The BlaR1–avibactam structure of the carbamoyl-enzyme intermediate revealed that avibactam is bound to the active-site serine in two orientations ∼180° to each other. Although a physiological role of the observed alternative pose remains to be validated, our structural results hint at the presence of a secondary sulfate-binding pocket that could be exploited in the design of future inhibitors of BlaR1/MecR1 sensor domains or the structurally similar class D β-lactamases. The MecR1–avibactam structure adopted a singular avibactam orientation similar to one of the two states observed in the BlaR1–avibactam structure. Given avibactam up-regulates expression of blaZ and pbp2a antibiotic resistance genes, we suggest further consideration and research is needed to explore what effects administering β-lactam–avibactam combinations have on treating MRSA infections.

scholarly journals Methicillin-Resistant Staphylococcus aureus in the Oral Cavity: Implications for Antibiotic Prophylaxis and Surveillance

2020 ◽  
Vol 13 ◽  
pp. 117863372097658
Author(s):  
Eric S Donkor ◽  
Fleischer CN Kotey
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Oral Cavity ◽  
Antibiotic Prophylaxis ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Resistance Genes ◽  
Methicillin Resistant ◽  
Commensal Flora ◽  
Methodological Approaches ◽  
Wide Usage

The oral cavity harbors a multitude of commensal flora, which may constitute a repository of antibiotic resistance determinants. In the oral cavity, bacteria form biofilms, and this facilitates the acquisition of antibiotic resistance genes through horizontal gene transfer. Recent reports indicate high methicillin-resistant Staphylococcus aureus (MRSA) carriage rates in the oral cavity. Establishment of MRSA in the mouth could be enhanced by the wide usage of antibiotic prophylaxis among at-risk dental procedure candidates. These changes in MRSA epidemiology have important implications for MRSA preventive strategies, clinical practice, as well as the methodological approaches to carriage studies of the organism.

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