Comparison of Cell Sizes of Methicillin-Resistant Staphylococcus aureus with Presence and Absence of the MecA Gene

2021 ◽  
Vol 83 (1) ◽  
pp. 68-77
Author(s):  
O. Berhilevych ◽  
◽  
V. Kasianchuk ◽  
M. Kukhtyn ◽  
P. Shubin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Cell Size ◽  
Meca Gene ◽  
Morphological Characteristics ◽  
Resistance Mechanisms ◽  
The Body ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Wide Range

Staphylococcus aureus is a pathogenic microorganism that causes a wide range of infectious diseases of humans and animals. Staphylococcus aureus produces a large number of toxins, in particular enterotoxins, which enter the body together with food and cause disorders in the gastrointestinal tract. Moreover, S. aureus has several mechanisms of antibiotic resistance, which greatly complicates prevention of bacteria spread as community-acquired and nosocomial infections. The aim of the work was to determine and compare the differences in size of methicillin-resistant strains of S. aureus with different resistance mechanisms by scanning electron microscopy (SEM). Methods. Disc diffusion method was used to establish the mechanism of antibiotic resistance of the obtained isolates. After description of antibiotic resistant and selection of S. aureus isolates with resistance to penicillin and oxicilin, an SEM of the strains and a further comparison of their morphological characteristics, in particular cell size, with the help of Djmaizer v.5.1.10 software was carried out. Results. 54 isolates of S. aureus, obtained from various environmental objects, dairy farms and food products, were tested. PCR revealed sequences of the mecA gene, which is responsible for bacteria resistance to beta-lactams. We determined the cells size of S. aureus isolates resistant to penicillin and oxycillin and performed a comparative analysis of their morphological characteristics using SEM. Conclusions. In the course of the study, it was found that S. aureus isolates with mecA gene (mecA+) have smaller cell size than S. aureus isolates without mecA gene (mecA-).

Evaluation of antibiotic resistance pattern and mecA gene frequency in methicillin-resistant Staphylococcus aureus strains collected from clinical specimens in Marand hospital and treatment centers, Iran

2021 ◽  
Author(s):  
Abolfazl Jafari-Sales ◽  
Zahra Sadeghi Deylamdeh ◽  
Afsoon Shariat
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Medical Centers ◽  
Wide Range

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods.  Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene.  The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics.  Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.

scholarly journals Prevalence and Antibiotic Resistance Mechanisms of Methicillin-Resistant Staphylococcus aureus isolates from Selected Hospitals in Ashanti Region, Ghana.

2021 ◽  
Author(s):  
Crystal Ngofi Zumbi ◽  
Vivian Etsiapa Boamah ◽  
Yaw Duah Boakye ◽  
Hayford Odoi ◽  
Christian Agyare
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Health Problem ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Efflux Pump ◽  
Meca Gene ◽  
Resistance Mechanisms ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Ashanti Region

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.

scholarly journals Mutation-Based Antibiotic Resistance Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Active Site ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Ligand Docking ◽  
Clinical Samples ◽  
Allosteric Site ◽  
Methicillin Resistant

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.

scholarly journals Antibiotic Resistance in Staphylococcus aureus in Patients Hospitalized in Imam Reza Hospital of Kermanshah, Iran (2016 - 2018)

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Mohammad Hossein Zamanian ◽  
Marya Shirvani ◽  
Alireza Janbakhsh ◽  
Babak Sayad ◽  
Siavash Vaziri ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Opportunistic Pathogen ◽  
Cross Sectional Study ◽  
Penicillin G ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
Healthcare Settings ◽  
Wide Range

Background: Staphylococcus aureus is an opportunistic pathogen, which often causes asymptomatic diseases. This bacterium could cause several disorders, ranging from skin infections to life-threatening diseases. S. aureus could also develop resistance to a wide range of antibiotics. Objectives: The present study aimed to investigate the prevalence and pattern of antibiotic resistance in isolated S. aureus in Imam Reza Hospital of Kermanshah, Iran. Methods: This descriptive cross-sectional study was conducted on 2,228 patients with a positive S. aureus culture who were admitted to Imam Reza Hospital during 2016 - 2018. In accordance with the CLSI protocol, bacterial isolates were separated using laboratory tests, and antibiotic susceptibility was assessed using the standard disk-diffusion method. Data analysis was performed in SPSS version 24. Results: Most of the S. aureus-positive cases were isolated from the emergency ward (43.7%), blood samples (40.1%), and urine samples (23.9%). The highest antibiotic resistance was observed against erythromycin, penicillin G, ofloxacin, cefoxitin, clindamycin, and piperacillin. With 93.3% and 81.8% sensitivity, vancomycin and teicoplanin were respectively the most effective antibiotics against S. aureus. Conclusions: According to the results, the prevalence of resistant S. aureus strains could be due to the long-term hospitalization of patients and the overuse of antibiotics in infection treatment. Therefore, proper monitoring and development of effective infection control methods are essential in these healthcare settings.

scholarly journals Antibiotic Resistance Profile and Methicillin-Resistant Encoding Genes of Staphylococcus aureus Strains Isolated from Bloodstream Infection Patients in Northern Vietnam

2019 ◽  
Vol 7 (24) ◽  
pp. 4406-4410
Author(s):  
Le Van Nam ◽  
Do Quyet ◽  
Pham Ngoc Hung ◽  
Tran Viet Tien ◽  
Kieu Chi Thanh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Meca Gene ◽  
Bloodstream Infections ◽  
Cross Sectional ◽  
Methicillin Resistant ◽  
Resistance Profile ◽  
Northern Vietnam ◽  
Antibiotic Resistance Profile ◽  
Encoding Genes

Background:  Evaluating the antibiotic susceptibility and resistance genes is essential in the clinical management of bloodstream infections (BSIs). Nevertheless, there are still limited studies in Northern Vietnam. AIM: This study aimed to determine the antibiotic resistance profile and methicillin-resistant encoding genes of Staphylococcus aureus (S. aureus) causing BSIs in Northern Vietnam. METHODS: The cross-sectional study was done from December 2012 to June 2014 in two tertiary hospitals in Northern Vietnam. Tests performed at the lab of the hospital. RESULTS:  In 43 S. aureus strains isolating, 53.5 % were MRSA. Distribution of gene for overall, MRSA, and MSSA strains were following: mecA gene (58.1 %; 95.7%, and 15%), femA gene (48.8%, 47.8%, and 50%), femB gene (88.4%, 82.6%, and 95%). Antibiotic resistance was highest in penicillin (100%), followed by erythromycin (65.1%) and clindamycin (60.5%). Several antibiotics were susceptible (100%), including vancomycin, tigecycline, linezolid, quinupristin/dalfopristin. Quinolone group was highly sensitive, include ciprofloxacin (83.7%), levofloxacin (86%) and moxifloxacin (86%). CONCLUSION:  In S. aureus causing BSIs, antibiotic resistance was higher in penicillin, erythromycin, and clindamycin. All strains were utterly susceptible to vancomycin, tigecycline, linezolid, quinupristin/dalfopristin.

scholarly journals Sensitivity to Antibiotics of Staphylococcus Aureus Strains, Able to Biofilm Formation

2021 ◽  
Vol 6 (3) ◽  
pp. 226-231
Author(s):  
A. O. Vashchenko ◽  
◽  
Yu. S. Voronkova ◽  
A. I. Vinnikov ◽  
T. N. Shevchenko ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Clavulanic Acid ◽  
Rapid Determination ◽  
Diffusion Method ◽  
Upper Respiratory Tract ◽  
Isolation And Identification ◽  
Methicillin Resistant ◽  
Opportunistic Bacteria ◽  
Amoxicillin Clavulanic Acid

The problem of respiratory diseases associated with staphylococcal carriers is considered to be one of the most acute in modern society due to its high prevalence and problems with treatment due to the high resistance of these bacteria to antibiotics. The purpose of the study was to determine the sensitivity of Staphylococcus aureus strains, able to form biofilm, isolated from the upper respiratory tract of human. Materials and methods. Bacteriological methods of isolation and identification of staphylococci, the method of rapid determination of the ability to form biofilm on a tablet and the disk-diffusion method of determining the susceptibility to antibiotics were used to perform the research. As a result of the conducted researches it was established that in the structure of pathogens of exacerbations of seasonal rhinitis S. aureus prevailed. It was isolated from 34 samples of biological material from the nose, which accounted for 69.4% of all examined cases of rhinitis. Staphylococcus spp. (6.1%) and Streptococcus spp. (24.5%) among the isolated strains of S. aureus, 27 (79.4%) had the ability to form a biofilm. A feature associated with antibiotic resistance is the ability of strains of microorganisms to form a biofilm, in which they acquire enhanced ability to survive under adverse environmental factors, including the use of drugs. Results and discussion. In our research we showed that more than 80% of film-forming strains were found to be susceptible to ciprofloxacin, amoxicillin / clavulanic acid and azithromycin. 4 (14.8%) are methicillin-resistant. Resistance to methicillin was detected simultaneously with resistance to ciprofloxacin (3 cases) and to azithromycin (2 cases), 1 strain was resistant to gentamicin and 2 – to tetracycline. 1 of the methicillin-resistant strains of S. aureus was multidrug-resistant (showed resistance to all studied antibiotics). Among non-biofilm strains, more than 80% of the strains were also sensitive to ciprofloxacin, amoxicillin / clavulanic acid and azithromycin. Sensitivity to tetracycline was low in both groups (42-63% sensitive). Conclusion. The prevalence of antibiotic resistance among clinical strains of opportunistic bacteria, unfortunately, shows an increasing trend. This requires constant monitoring of susceptibility to antimicrobial drugs in order to develop schemes of rational antibiotic therapy, taking into account the individualized approach to patients. In this sense, it is promising when studying the biological properties of clinical isolates to determine not only the resistance to antibiotics, but also their ability to form a biofilm

scholarly journals Profile of antibiotic-resistant and presence of methicillin-resistant Staphylococcus aureus from nasal swab of dogs from several animal clinics in Surabaya, Indonesia

2020 ◽  
Vol 6 (1) ◽  
pp. 90-94
Author(s):  
Vega Decline ◽  
Mustofa Helmi Effendi ◽  
Reina Puspita Rahmaniar ◽  
Sheila Marty Yanestria ◽  
Nenny Harijani
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Nasal Swab ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Oxacillin Resistance

Aim: The research was to investigate the antibiotic resistance profile and to screen for methicillin-resistant Staphylococcus aureus (MRSA) from nasal mucosa swab of dogs. Materials and Methods: The samples were collected from three pet clinics, three K9 units, one veterinary teaching hospital, and one kennel in Surabaya. Of the 50 total samples, 24 confirmed S. aureus strains, which were used for antibiotic sensitivity tests using a disk diffusion method and screening of MRSA used oxacillin resistance screening for base (ORSAB). Results: This study showed that there were differences in antibiotic resistance patterns among different locations. Fourteen isolates were screened for MRSA by culture on ORSAB. Conclusion: MRSA carriage was found on nasal swab of dogs, and dogs can act as reservoir of MRSA for spreading to human health. Keywords: antibiotic-resistant, dogs, methicillin-resistant Staphylococcus aureus, Staphylococcus aureus.

scholarly journals Biofilm formation and antimicrobial resistance in methicillin-resistant Staphylococcus aureus isolated from burn patients, Iran

2014 ◽  
Vol 8 (12) ◽  
pp. 1511-1517 ◽  
Author(s):  
Solmaz Ohadian Moghadam ◽  
Mohammad Reza Pourmand ◽  
Farzaneh Aminharati
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Burn Patients ◽  
Burn Wound ◽  
Methicillin Resistant ◽  
Therapeutic Decisions

Introduction: Burns are the most serious forms of trauma and a major cause of mortality worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of burn wound infections; treatment has faced serious problems due to antibiotic resistance in these strains. Biofilm formation, which increases antibiotic resistance capabilities and is considered to be a virulence factor, also causes treatment failure and recurrent staphylococcal infections in burn patients. Methodology: A total of 135 pus/wound swabs were collected; S. aureus was identified by confirmatory tests. The icaA/D and mecA genes were detected in DNA extracts by polymerase chain reaction assay separately. To determine the prevalence of biofilm formation, a modified Congo red agar and the microtiter plate method were used. Investigation of antibiotic resistance was performed using the disk diffusion method. Results: S. aureus (48.87%) was identified in 65 (48.87%) samples, of which 40 (61.53%) were confirmed to be MRSA. Among MRSA and methicillin-sensitive S. aureus (MSSA) isolates, 97.5% and 60% produced biofilm, respectively. Resistance of MRSA isolates to amikacin, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, mupirocin, rifampin, tetracycline, and tobramycin was 64.1%, 76.92%, 51.28%, 87.18%, 71.8%, 10.26%, 5.13%, 89.74%, and 61.54%, respectively. All MRSA and MSSA isolates were susceptible to fusidic acid, linezolid, teicoplanin, tigecycline, and vancomycin. Conclusions: The high prevalence of biofilm-producing, drug-resistant S. aureus isolates in our study suggests that epidemiological studies on the characteristics of common strains found in burn centers and a definition of their antibiotic resistance pattern would be helpful for therapeutic decisions.

scholarly journals Antibacterial effects of 4 methanol plant extracts (Lamiaceae) against 10 Methicillin Resistant Staphylococcus aureus isolates

2015 ◽  
Vol 9 (2) ◽  
pp. 51-54
Author(s):  
Maryam Paydar ◽  
Ashraf Kariminik
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Plant Extracts ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibacterial Effect ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Zataria Multiflora ◽  
Methicillin Resistant ◽  
Herbal Therapies

Antibiotic resistance has paved the way for replacing conventional medications with herbal therapies that supposedly have less side-effect. This research is an experimental study and a fundamental- functional one. The present study aimed to investigate the antibacterial effect of 4 plant extracts from Lamiaceae on 10 methicillin resistant Staphylococcus aureus isolates. Methanol extracts were prepared by maceration method for 10 days in room temperature and then filtered with wathman paper No.1 and concentrated by rotary evaporator system. Different concentration of each extract were prepared in dimethyl sulfoxide: methanol (1:1 v/v) and bioassayed on 10 MRSA isolates by agar well diffusion method in Muller-Hinton agar medium. Plates were incubated in 37°C for 24 hours. After incubation period, zone of inhibition was measured in millimeter and the antibacterial effect of extracts were evaluated. According to antibiogram test, some of Staphylococcus aureus isolates were sensitive to the used extracts with different MIC.MIC values about all Staphylococcus aureus isolates about Zataria multiflora, Mentha longifolia, Ziziphor clinopodioide and Satureja hortensis were 15, 30, 30 and 15 mg/ml respectively. Because of regarding the fact that antibiotic resistance is growing, according to the acquired results we expect to be able to use plant extracts against Staphylococcus aureus resistant to meticillin in controling the infections or as preservatives in food sciences and in the next step separating of effective substances were suggested.DOI: http://dx.doi.org/10.3126/ijls.v9i2.12045 International Journal of Life Sciences 9 (2) : 2015; 51-54

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