scholarly journals Antimicrobial Resistance in Staphylococcus aureus

2021 ◽  
Author(s):  
Riya Mukherjee ◽  
Anjali Priyadarshini ◽  
Ramendra Pati Pandey ◽  
Vethakkani Samuel Raj

Staphylococcus aureus is a Gram-Positive bacteria that are responsible to cause skin infections and also shows toxic shock syndrome. Several antibiotics were given against the S. aureus infections but eventually, the prevalence of multidrug resistance of Staphylococcus aureus started emerging. Since then Methicillin-resistant Staphylococcus aureus strains (MRSA)were very common which causes nosocomial infections. Microorganisms for the need of the survival undergoes mutational changes either in their chromosomal DNA/RNA which confers the resistance. One of the famous examples is the resistance against methicillin in Staphylococcus aureus. The evolution of S. aureus is successful in developing multiple resistant strains. Plasmids are capable of carrying the resistant genes and also several toxic genes. In a recent study, it has been observed that drug resistance genes are located in the R plasmids and they are also responsible in conferring multi drug resistance and induce less utilization of multiple antimicrobial therapy. MRSA was not only resistant to methicillin, studies proved MRSA strains were resistant to macrolides, tetracyclines, chloramphenicol. Resistance to vancomycin was very evidently observed, and its transfer among the population and rising of resistant strains was becoming a major threat globally. The resistance of all these antimicrobial agents against the pathogenic microorganisms are taking a rise in some patients due to prolong use of the antimicrobial agents by these patients. The multi drug resistance has enhanced the mortality and morbidity rate which referred to the infecting agents as the “Super Bugs”. Survival of the microorganisms has increased due to the gradual development of extensive resistance against varied antimicrobial drugs. Possible treatments with combinations are found to be the only hope for infections against S. aureus. Few drugs are in development such as Dalbavancin, Oritavancin, Tigecycline. These are the possible treatments upon which the work is going on to reduce the resistance against the invasive MRSA. This chapter highlights the profiles of Staphylococcus aureus and the resistance patterns along with transmission and the role of the plasmid in transmitting the resistance.


2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Ana Verónica Martínez-Vázquez ◽  
Iliana Berenice Guardiola-Avila ◽  
Rebeca Flores-Magallón ◽  
Gildardo Rivera ◽  
Virgilio Bocanegra-García

Abstract Purpose Among the principal microorganisms transmitted to humans by foods of animal origin, Staphylococcus aureus stands out, causing a variety of diseases and with a wide potential for acquiring antimicrobial resistance. This work aimed to determine the prevalence of S. aureus, its multi-drug resistance (MDRSA), and the identification of methicillin-resistant Staphylococcus aureus (MRSA) in retail beef and pork in the state of Tamaulipas, Mexico. Methods S. aureus strains isolated from retail meat were characterized by microbiological and molecular methods to determine phenotypic drug-resistance and detect MRSA strains. Results Of the 106 samples (54 from beef and 52 from pork) from 11 different cities, we detected a prevalence of S. aureus of 44.3% (47/106). A total of 87 S. aureus strains were identified; these presented 54 resistance patterns to different antimicrobials with a high prevalence of MDRSA (85%) and a low prevalence of MRSA strains (3%). Conclusion These results indicate the presence of MDRSA and MRSA in retail beef and pork in Tamaulipas, representing a high risk for consumer health.



2015 ◽  
Vol 78 (6) ◽  
pp. 1142-1146 ◽  
Author(s):  
ALESSANDRA RIVA ◽  
ELISA BORGHI ◽  
DANIELA CIRASOLA ◽  
SILVIA COLMEGNA ◽  
FRANCESCA BORGO ◽  
...  

Staphylococcus aureus is a known major cause of foodborne illnesses, and raw milk and dairy products are often contaminated by enterotoxigenic and antimicrobial-resistant S. aureus strains. In the present study, 35 S. aureus strains were isolated from 383 raw milk samples collected from various dairy herds in the province of Milan (northern Italy). The isolates were characterized based on their antimicrobial susceptibility patterns and the presence of genes encoding staphylococcal enterotoxins (sea, seb, sec, sed, and see). About half (45.7%) of the strains were enterotoxigenic, and 37.1% were resistant to at least one of the antimicrobial drugs tested. Seven (20%) of 35 isolates were identified as methicillin-resistant S. aureus (MRSA), and SCCmec typing performed with a multiplex PCR assay revealed the presence of gene cassettes IV and V, typical of community-acquired MRSA, and I and II, characteristic of health care–associated MRSA. The MRSA strains were evaluated for the presence of the Panton-Valentine leukocidin gene, but this gene was not found. The results of the present study revealed the presence of toxin-producing S. aureus and MRSA strains in raw milk. MRSA and enterotoxigenic S. aureus in dairy farms are an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for monitoring and controlling the presence of S. aureus, especially MRSA, in dairy products.



2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Mahdi Mostafa ◽  
Seyed Davar Siadat ◽  
Fereshteh Shahcheraghi ◽  
Farzam Vaziri ◽  
Alireza Japoni-Nejad ◽  
...  


2020 ◽  
Vol 1 (1) ◽  
pp. 9-15
Author(s):  
Mehwish Tanveer ◽  
Hira Musaddiq ◽  
Atia Iqbal ◽  
Sarwat Saleem ◽  
Sadia Iqbal ◽  
...  

2-Substituted 1,3-Thiazolidine-4-Carboxylic Acids (1-11) were synthesized and screened for their anti-methicillin-resistant Staphylococcus aureus (MRSA) potential. The synthesized compounds were evaluated for their antibacterial activities against four MRSA strains MRSA I, VI, VII and VIII with accession numbers KU662352, KR862285, KR862291 and KU662354 respectively by well diffusion method. In addition, antibacterial evaluations were also performed for gram positive strain Bacillus subtilis and gram-negative strains klebsiella pneumoniae and pseudomonas aeruginosa using same method. Most of the synthesized thiazolidine-4-carboxylic acid derivatives exhibited better antibacterial activities against studied bacterial strains. Amongst the synthesized compounds, 8-10 were found to possess significant activity (Zone in mm) against methicillin-resistant Staphylococcus aureus in addition to the other studied bacterial strains.



2016 ◽  
Vol 13 (7) ◽  
pp. 668-675
Author(s):  
Saba Farooq ◽  
. Atia-tul-Wahab ◽  
Ali Azarpira ◽  
. Atta-ur-Rahman ◽  
M. Iqbal Choudhary


2014 ◽  
Vol 143 (3) ◽  
pp. 470-477 ◽  
Author(s):  
D. BHATTACHARYA ◽  
H. BHATTACHARYA ◽  
D. S. SAYI ◽  
A. P. BHARADWAJ ◽  
M. SINGHANIA ◽  
...  

SUMMARYThis study is a part of the surveillance study on childhood diarrhoea in the Andaman and Nicobar Islands; here we report the drug resistance pattern of recent isolates ofShigellaspp. (2006–2011) obtained as part of that study and compare it with that ofShigellaisolates obtained earlier during 2000–2005. During 2006–2011, stool samples from paediatric diarrhoea patients were collected and processed for isolation and identification ofShigellaspp. Susceptibility to 22 antimicrobial drugs was tested and minimum inhibitory concentrations were determined for third-generation cephalosporins, quinolones, amoxicillin-clavulanic acid combinations and gentamicin. A wide spectrum of antibiotic resistance was observed in theShigellastrains obtained during 2006–2011. The proportions of resistant strains showed an increase from 2000–2005 to 2006–2011 in 20/22 antibiotics tested. The number of drug resistance patterns increased from 13 in 2000–2005 to 43 in 2006–2011. Resistance to newer generation fluoroquinolones, third-generation cephalosporins and augmentin, which was not observed during 2000–2005, appeared during 2006–2011. The frequency of resistance inShigellaisolates has increased substantially between 2000–2006 and 2006–2011, with a wide spectrum of resistance. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs.



2015 ◽  
Vol 59 (5) ◽  
pp. 2583-2587 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Nachum Kaplan ◽  
Ronald N. Jones ◽  
David J. Farrell

ABSTRACTStaphylococcus aureusand coagulase-negative staphylococci (CoNS) are responsible for a wide variety of human infections. The investigational antibacterial Debio1450 (previously AFN-1720), a prodrug of Debio1452 (previously AFN-1252), specifically targets staphylococci without significant activity against other Gram-positive or Gram-negative species. Debio1452 inhibits FabI, an enzyme critical to fatty acid biosynthesis in staphylococci. The activity of Debio1452 against CoNS, methicillin-susceptibleS. aureus(MSSA), and methicillin-resistantS. aureus(MRSA), including significant clones, was determined. A globally diverse collection of 574 patient isolates from 35 countries was tested that included CoNS (6 species, 103 strains), MSSA (154 strains), MRSA (163 strains), and molecularly characterized strains (includingspa-typed MRSA clones; 154 strains). The isolates were tested for susceptibility by CLSI broth microdilution methods against Debio1452 and 10 comparators. The susceptibility rates for the comparators were determined using CLSI and EUCAST breakpoint criteria. AllS. aureusand CoNS strains were inhibited by Debio1452 concentrations of ≤0.12 and ≤0.5 μg/ml, respectively. The MIC50s for MSSA, MRSA, and molecularly characterized MRSA strains were 0.004 μg/ml, and the MIC90s ranged from 0.008 to 0.03 μg/ml. The MICs were higher for the CoNS isolates (MIC50/90, 0.015/0.12 μg/ml). AmongS. aureusstrains, resistance was common for erythromycin (61.6%), levofloxacin (49.0%), clindamycin (27.6%), tetracycline (15.7%), and trimethoprim-sulfamethoxazole (7.0%). Debio1452 demonstrated potent activity against MSSA, MRSA, and CoNS. Debio1452 showed significantly greater activity overall (MIC50, 0.004 μg/ml) than the other agents tested against these staphylococcal species, which included dominant MRSA clones and strains resistant to currently utilized antimicrobial agents.



1992 ◽  
Vol 108 (1) ◽  
pp. 87-97 ◽  
Author(s):  
S.-R. Lin ◽  
S.-F. Chang

SUMMARYOne hundred and twenty-eight shigella strains isolated from newborn and infant human faecal specimens at Kaohsiung Medical College Hospital in Taiwan were serogrouped, serotyped and examined for drug-resistance patterns and for the presence of plasmids. Forty-seven pre cent of the isolates were found to belong to theShigella sonneiserogroup, 41%to theS.flexnerigroup,9%to theS.boydiigroup and 3%to theS.dysenteriaegroup.The serotype with the greatest number of strains wasS.sonneiI. (29 %) followed byS. flexneri1 (27%). Each strain was tested for resistance to 11 antimicrobial agents. Eighty-eight per cent of the strains were resistant to tetracycline, 87% to chloramphenicol, 84% to streptomycin, 52% to ampicillin, 25% to nalidixic acid, 29% to kanamycin, 11 % to cephalothin, 11% to neomycin, 10% to cotrimoxazole, 1% to amikacin and none to gentamicin. The most prevalent resistance pattern was ApCmSmTc (28%). Clinical isolates demonstrating multiple resistance were found to harbour a large transmissible plasmid of 45–75 MDa while isolates without multiple resistance did not. Two large virulence plasmids of 123 and 110 MDa were found in 12 strains ofS. flexneriand 4 strains ofS. sonneiphase I. Small plasmids of 4·5, 4·2, 3·5, 2·8, 2·5. 2·0 and 1·5 MDa were also present in all strains. These small plasmids were species specific and can be used as marker plasmids to identify species.



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