Molecular Characterization and Antimicrobial Susceptibility Patterns of Methicillin-Resistant Staphylococcus aureus Isolates in Tabriz, Northwest of Iran (original) (raw)
Related papers
Infection and Drug Resistance
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most pathogens associated with health care. Molecular typing methods are vital for outbreak investigations of MRSA. The aim of this study was characterization of SCCmec, spa types and multidrug resistant of methicillin-resistant Staphylococcus aureus isolates in Ahvaz, Iran. Methods: A total of 50 MRSA isolates were determined by using the phenotypic method and mecA gene. Antibiotic resistance profile and SCCmec types were screened using disc diffusion method and PCR, respectively. For spa typing of MRSA isolates, two molecular typing methods including the PCR-sequencing and high-resolution melting (HRM) analysis were used. Results: In the present study, the highest sensitivity of MRSA was to vancomycin and linezolid and the lowest to clindamycin. In the MRSA isolates, 22% were XDR and 78% were MDR. SCCmec type III was found commonly among MRSA. Based on PCR-sequencing and HRM results, 10 different spa types were identified. The spa types t037 and t030 were the most common in this study. Conclusion: This study emphasizes the spa variation among MRSA isolates, which may be considered as an important criterion when treating staphylococcal infections. Accurate and early detection of MDR, XDR, or even PDR MRSA isolates strains must be commenced by all clinical microbiology laboratories to reduce the menace of antimicrobial resistance.
Chemotherapy, 2021
Background: Emergence and prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) has become a major universal health concern, limiting therapeutic options. Methods: In the North side of Iran, during the years 2015 to 2017, a total number of 37 MRSA isolates, including 19 clinical isolates from hospitalized patients and 18 colonizing isolates from health care workers were identi ed from three hospitals, in Gorgan, North of Iran. Antimicrobial susceptibility test was performed using the disk diffusion method and E-test. The presence of virulence and antibiotic resistance determinants were evaluated by PCR. The genotypic characterization was further analyzed using multi-locus sequence, spa, SCCmec, and agr typing. Results: The frequency of MRSA among S. aureus isolates was 38.14% (37/97). The most frequent S. aureus resistant isolates were found to be obstinate against penicillin (98%) and gentamicin (82.5%). Additionally, the lowest resistance rates were found against daptomycin (0%), vancomycin (2.7%), and quinupristin-dalfopristin (5.4%). All MRSA isolates were susceptible to daptomycin with MIC 50 /MIC 90 of 0.25/0.5 µg/ml. One isolate belonging to the ST239-SCCmecIII/t037 clone (MIC≥16μg/ml) was resistant to vancomycin. All but one isolate that shares the ST22-SCCmec IV/t790 strain were positive for both tsst and pvl genes. The most predominant MRSA isolates (27%) were associated with the ST239-SCCmec III/t037 clone; and followed by ST239-SCCmec III/t924 (16.2%). Conclusions: In our study, circulating MRSA strains were genetically diverse with a high prevalence of the ST239-SCCmecIII/t037 clone. These ndings emphasize the need for future and continuous surveillance studies on MRSA to prevent the dissemination of multidrug resistance and existing MRSA clones in an effective manner. [2, 13]. The geographical differences in the genotypic characteristic of MRSA have been reported [2]. In Asia, there is signi cant divergence among countries and regions with respect to prevalence of MRSA; in fact, ST22-SCCmec IV/t790 and ST239-SCCmec III/t037 clones are predominant among patients in Iran [2, 14], and so is ST239-spa t037 and ST5-spa t002 in China [15]. On the other hand, in many regions in Asia [16, 17], sequence type 239 (ST239) is most prevalent, where, in UK, ST36 and ST30 are the most common types [18]. With this background, we are evaluating the molecular characteristics, antibiotic resistance patterns, and virulence genes pro les of MRSA isolates obtained from two kinds of study populations, namely hospitalized patients and health care workers (HCWs) in Gorgan, North of Iran. Methods Study Design and Sample Collection of S. aureus Isolates This cross-sectional study was conducted from January 2, 2016 to October 28, 2018 in three hospitals (total of 920-beds) in Gorgan, North of Iran. Written informed consent was obtained from all the patients or HCWs and the study protocol was approved by the Ethics Committee in Golestan University of Medical Sciences (No. 31078693122419), and was conducted in accordance with the Declaration of Helsinki. The demographic pro les of patients and HCWs were recorded. We identi ed S. aureus and MRSA in hospitalized patients and HCWs as well (Table 1). Only the rst sample of each patient was included in the study. In case of HCWs, samples were collected from both anterior nares. 302 unduplicated clinical samples (blood, urine, wound, sputum, and others) were obtained from in-patients, out of which S. aureus and MRSA were identi ed in 53 (17.5%), and 19 specimens (6.29%), respectively. Likewise, 351 unduplicated non-clinical samplings from the anterior nares of HCWs were carried out. All the samples were sent for bacterial culturing and identi cation, using Gram staining, and standard biochemical tests, such as catalase, tube coagulase, DNase test, and mannitol fermentation [19]. The identi cation process of all S. aureus isolates was con rmed by using genotypic methods for the presence of nucA, and femA genes [2, 20]. Data on department and period of hospitalization, clinical symptoms, antibiotic usages, and underlying conditions were recorded.
Bosnian Journal of Basic Medical Sciences, 2015
Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA. We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing. The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003.We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals.
Introduction: Methicillin-resistant Staphylococcus aureus is commonly a cause of nosocomial infections. The increase in infection rates caused by this bacterium in developing countries has led to many problems. The aim of this study is to determine the antibiotic resistance pattern in methicillin- resistant S. aureus strains isolated from clinical specimens. Methods: In this cross-sectional study, 256 isolates of S. aureus were collected from Tabriz hospitals and treatment centers. The isolates were identified by standard laboratory methods and cultured in a specific environment. Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) strains was made through phenotypic method. In order to evaluate antibiotic susceptibility patterns of strains, a disk diffusion method based on CLSI protocol was also performed. Data was analyzed by Chi-square test and SPSS. P value of <0.05 was considered as significant. Results: Out of 256 examined samples, 197 (76.95%) of them were methicillin-resistant Staphylococcus aureus. The phenotypic evaluation of the antibiotic resistance pattern of methicillin-resistant S. aureus showed that the highest resistance was for 100% penicillin antibiotics, 94.22% co- amoxiclav and 81.22% gentamicin antibiotics and the lowest resistance was observed as chloramphenicol (16.75%). There was no significant relationship between age, sex, and MRSA infections (P> 0.05). Conclusion: High resistance S. aureus to penicillin, co-amoxiclav, gentamicin and also the high frequency of isolation of MRSA of hospital studied samples are remarkable. The present study demonstrates the need for continuous monitoring of antimicrobial susceptibility in S. aureus in order to determine the optimal drug regimens
Genotypic and phenotypic characteristics of Methicillin resistant Staphylococcus aureus MRSA strains
Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA. We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing. The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003.We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals.
Antimicrobial Resistance and Infection Control, 2020
Background: The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan. Methods: A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antimicrobial resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multilocus sequence typing and SCCmec typing. Results: Of 146 Staphylococcus aureus isolates, 24 (16.4%) isolates were identified as MRSA strains. According to antimicrobial susceptibility testing the highest resistance rates were seen for tetracycline, erythromycin, ciprofloxacin and gentamicin. All of Staphylococcus aureus isolates were susceptible to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCCmec types were obtained among MRSA strains including 16 (66.7%) SCCmec type V, 3 (12.5%) SCCmec type III and 5 (20.8%) SCCmec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%), cna (25.0%), fnbB (16.6%), ebps 5 (20.8%), and the fnbA, bbp and clfA genes were not detected in any MRSA isolate. MLST analysis revealed 11 sequence types among MRSA isolates as follows:
Journal of Advanced Laboratory Research in Biology, 2018
The prevalence of multidrug-resistant Staphylococcus aureus has increased during the last few years in healthcare facilities, and methicillin-resistant Staphylococcus (MRSA) in particular has emerged as a serious nosocomial pathogen because it is difficult to destroy and treat. Therefore this study was carried on to find out the frequency of MRSA among S. aureus isolates as well as to study their susceptibility profile. In this study, 43 strains of S. aureus were recovered from different departments at Sebha medical center and their antibiotic resistance profile was studied using Kirby Bauer disc diffusion method. Out of all 43 isolates, 16% were detected as MRSA using cefoxitin disk test. The strains that are resistant to erythromycin were further tested for inducible clindamycin resistance (ICR) using D-test. In this study, two strains showed ICR phenotype. While all isolates were 100% sensitive to vancomycin, the majority of isolates were resistant to ß-lactam group antibiotics. ...
2020
Background: The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan. Methods: A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antibiotic resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multi-locus sequence type and SCC mec typing. Results: Of 146 Staphylococcus aureus isolates 24 (16.4%) isolates identified as MRSA strains. According to antibiotic susceptibility testing the highest resistance rates were seen to erythromycin, cefoxitin and clindamycin. All of Staphylococcus aureus isolates were sensitive to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCC mec types were obtained among MRSA strains including 16 (66.7%) SCC mec type V, 3 (12.5%) SCC mec type III and 5 (20.8%) SCC mec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%) , cna (25.0%), fnbB (16.6%) , ebps 5 (20.8%), and fnbA , bbp and clfA genes were not detected. MLST analysis revealed 11 sequence types among MRSA isolates as follows:
Background and Objective: Staphylococcus aureus is one of the important factors causing nosocomial infections. The emergence of antibiotic-resistant Staphylococcus strains to Methicillin and other antibiotics has brought about several problems in treatment of the infections caused by Staphylococcus strains. The aim of this study is to identify antibiotic resistance patterns of Methicillin-resistant Staphylococcus aureus isolates from patients in selected hospitals in Isfahan. Materials and Methods: In this descriptive cross-sectional study, a total of 300 samples were isolated from hospital patients in Isfahan. Clinical strains were investigated phonotypical characterization like Gram stain, catalase, coagulase and carbohydrate fermentation to identify SA, then disk diffusion test was performed on SA based on CLSI to isolate MRSA, in addition antibiotic sensibility pattern obtained using Oxacillin, Tetracycline, Clindamycin, Rifampin, Ampicillin, Ciprofloxacin, Gentamicin, Cotrimoxazole, Vancomycin. The PCR was performed for the detection of the mecA gene in all the MRSA isolates. Results: In this study, 210 (70%) samples in a total of 300 isolates of Staphylococcus aureus were Methicillin-resistant. Evaluation and assessment of antibiotic resistance in MRSA isolates showed the greatest resistance to Oxacillin (100%), Tetracycline (97%), Clindamycin (92%), Rifampin (75%), Ampicillin (70%), respectively, while the lowest levels of resistance were observed to antibiotics Ciprofloxacin (61%), Gentamicin (50%), Cotrimoxazole (34%), and Vancomycin (0%), respectively. The implication of this high resistance is that Methicillin-resistant Staphylococcus aureus infections should be treated with more precaution and not with Penicillin and other ineffective antibiotics. The presence of mecA gene in all isolates was confirmed by PCR. Conclusion: In this study, the spectrum of antibiotic resistance in MRSA isolates is similar to other studies. The Effectiveness of Tetracycline, Rifampin and Clindamycin is still very low on MRSA samples.