Detection of antibiotic resistance genes associated with methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci in hospital air filter dust by PCR

Aerobiologia ◽  
2011 ◽  
Vol 28 (2) ◽  
pp. 285-289 ◽  
Author(s):  
Christopher N. Drudge ◽  
Sigmund Krajden ◽  
Richard C. Summerbell ◽  
James A. Scott
2019 ◽  
Vol 17 (6) ◽  
pp. 930-943 ◽  
Author(s):  
Adegboyega O. Oladipo ◽  
Oluwatosin G. Oladipo ◽  
Cornelius C. Bezuidenhout

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.


2020 ◽  
Vol 295 (32) ◽  
pp. 10870-10884 ◽  
Author(s):  
J. Andrew N. Alexander ◽  
Mariia Radaeva ◽  
Dustin T. King ◽  
Henry F. Chambers ◽  
Artem Cherkasov ◽  
...  

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.


2020 ◽  
Vol 13 ◽  
pp. 117863372097658
Author(s):  
Eric S Donkor ◽  
Fleischer CN Kotey

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.


Open Biology ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 170094 ◽  
Author(s):  
Mehul Jani ◽  
Soham Sengupta ◽  
Kelsey Hu ◽  
Rajeev K. Azad

Staphylococcus aureus is a versatile pathogen that is capable of causing infections in both humans and animals. It can cause furuncles, septicaemia, pneumonia and endocarditis. Adaptation of S. aureus to the modern hospital environment has been facilitated, in part, by the horizontal acquisition of drug resistance genes, such as mecA gene that imparts resistance to methicillin. Horizontal acquisitions of islands of genes harbouring virulence and antibiotic resistance genes have made S. aureus resistant to commonly used antibiotics. To decipher genomic islands (GIs) in 22 hospital- and 9 community-associated methicillin-resistant S. aureus strains and classify a subset of GIs carrying virulence and resistance genes as pathogenicity and resistance islands respectively, we applied a host of methods for localizing genomic islands in prokaryotic genomes. Surprisingly, none of the frequently used GI prediction methods could perform well in delineating the resistance islands in the S. aureus genomes. Rather, a gene clustering procedure exploiting biases in codon usage for identifying horizontally transferred genes outperformed the current methods for GI detection, in particular in identifying the known islands in S. aureus including the SCC mec island that harbours the mecA resistance gene. The gene clustering approach also identified novel, as yet unreported islands, with many of these found to harbour virulence and/or resistance genes. These as yet unexplored islands may provide valuable information on the evolution of drug resistance in S. aureus .


2020 ◽  
Author(s):  
Roya Chabi

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is considered to be one of the most important causes of food-borne diseases. The present investigation was done to assess the phenotypic and genotypic characterization and distribution of Staphylococcal cassette chromosome mec types and Panton–Valentine leukocidin gene in the MRSA strains isolated from raw meat samples. Six-hundred and eighty meat samples were collected and cultured. MRSA strains were subjected to disk diffusion and Polymerase Chain Reaction. One-hundred and thirty-five out of 680 (18.38%) raw meat samples were positive for S. aureus. Seventy-nine out of 125 (63.20%) S. aureus strains were determined as MRSA. Raw sheep meat samples (75%) had the highest prevalence of MRSA, while raw camel had the lowest (50%). Fifty-eight out of 79 (73.41%) MRSA strains harbored the PVL gene. SCCmec IVa (39.65%), V (22.41%) and III (10.34%) were the most commonly detected types in the MRSA strains. MRSA strains harbored the highest prevalence of resistance against penicillin (100%), tetracycline (100%), gentamicin (65.51%) and erythromycin (56.89%). AadA1 (58.62%), tetK (56.89%), msrA (41.37%) and vatA (36.20%) were the most commonly detected antibiotic resistance genes. Simultaneous presence of PVL and antibiotic resistance genes in multi-drug resistant MRSA strains specifies significant public health problem.


Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1121
Author(s):  
Nimat Ullah ◽  
Hamza Arshad Dar ◽  
Kanwal Naz ◽  
Saadia Andleeb ◽  
Abdur Rahman ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) is a multi-drug resistant and opportunistic pathogen. The emergence of new clones of MRSA in both healthcare settings and the community warrants serious attention and epidemiological surveillance. However, epidemiological data of MRSA isolates from Pakistan are limited. We performed a whole-genome-based comparative analysis of two (P10 and R46) MRSA strains isolated from two provinces of Pakistan to understand the genetic diversity, sequence type (ST), and distribution of virulence and antibiotic-resistance genes. The strains belong to ST113 and harbor the SCCmec type IV encoding mecA gene. Both the strains contain two plasmids, and three and two complete prophage sequences are present in P10 and R46, respectively. The specific antibiotic resistance determinants in P10 include two aminoglycoside-resistance genes, aph(3’)-IIIa and aad(6), a streptothrin-resistance gene sat-4, a tetracycline-resistance gene tet(K), a mupirocin-resistance gene mupA, a point mutation in fusA conferring resistance to fusidic acid, and in strain R46 a specific plasmid associated gene ant(4’)-Ib. The strains harbor many virulence factors common to MRSA. However, no Panton-Valentine leucocidin (lukF-PV/lukS-PV) or toxic shock syndrome toxin (tsst) genes were detected in any of the genomes. The phylogenetic relationship of P10 and R46 with other prevailing MRSA strains suggests that ST113 strains are closely related to ST8 strains and ST113 strains are a single-locus variant of ST8. These findings provide important information concerning the emerging MRSA clone ST113 in Pakistan and the sequenced strains can be used as reference strains for the comparative genomic analysis of other MRSA strains in Pakistan and ST113 strains globally.


2021 ◽  
Vol 18 (2) ◽  
pp. 155-171
Author(s):  
Patrick O. Olorunfemi ◽  
Ndidi C. Ngwuluka ◽  
Josiah A. Onaolapo ◽  
Yakubu K.E. Ibrahim

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


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