Emergence of SCCmec Type I Obtained From Clinical Samples in Shiraz Teaching Hospitals, South-West of Iran

Determination of Virulence Factors and Resistance Profile of Methicillin-Resistant Staphylococcus aureus Strains among Different Types of spa, agr, and SCCmec

In order to restrict the spread of methicillin-resistant S. aureus (MRSA) in hospitals, it is necessary to characterize isolates rapidly and precisely. The objective of this study was to determine virulence factors and resistance profiles of MRSA strains among spa, agr, and SCCmec types. In total, 55 MRSA isolates were collected from clinical specimens. The MRSA isolates were characterized by antimicrobial susceptibility testing, virulence genes, agr typing, spa typing, and SCCmec typing. According to our findings, all MRSA strains were resistant to cefoxitin; 88% and 86.7% of which were resistant to erythromycin and clindamycin, respectively. Type II agr was predominant with 54.54% frequency. Among 27 different spa types, type t030 was most frequently (25.45%). Most MRSA isolates (63.3%) were SCCmec type III. The pvl and tst genes were found in 25.3% and 32.7% of MRSA isolates, respectively. Among the MRSA strains, ermA, ermB, and ermC were present in 50%, 33.3%, and 57.3% of cases, respectively. In addition, 43 of the 55 MRSA strains (78%) harbored aminoglycoside resistance genes. The results of our study revealed that the MRSA rate in our region is dramatically high. Better infection control guidelines in hospitals, as well as ongoing epidemiological surveillance studies, could be strongly suggested for effective prevention of the spread of MRSA to inpatients.

Genotypic and phenotypic characterisation of clinical isolates of methicillin-resistant Staphylococcus aureus in two different geographical locations of Iran

Background

Methicillin-resistant Staphylococcus aureus (MRSA) has become more prevalent all over the world and it is important to determine MRSA prevalence and typing in different regions. The present study was carried out to determine the prevalence and frequency of circulating molecular types of MRSA isolates as well as their antibiotics susceptibility in Tabriz and Kerman cities of Iran.

Materials and Methods

A total of 230 S. aureus isolates were collected from Tabriz (n=125) and Kerman (n=105) during January to December 2018. MRSA isolates were identified by PCR amplification of nuc and mec A genes. Antibiotic susceptibility of MRSA isolates were determined by Kirby-Bauer disk diffusion method. Multiplex PCR was exploited to detect various types of SCCmec.

Results

The MRSA prevalence was 51/125 (40.8%) in Tabriz and 60/105 (57.1%) in Kerman. Overall, 36/51 (70.58%) and 15/51 (29.41%) isolates and 37/60 (61.66%) and 23/60 (38.34%) isolates were isolated from inpatients and outpatients in Tabriz and Kerman, respectively. Almost all of the isolates were resistant to penicillin and all of them were sensitive to linezolid. Thirty five (68.2%) and 34(56.6%) of MRSA isolates in Tabriz and Kerman were determined as MDR, respectively. SCCmec typing showed that the frequent SCCmec type in both Tabriz and Kerman cities was SCCmec III (56.86% and 55%, respectively).

Conclusion

The high prevalence of MRSA makes it necessary to revisit the antibiotics administration by physicians. Indeed, periodic evaluation of antibacterial susceptibility patterns of the MRSA strains is required for efficient treatment of MRSA infections.

Evaluation of Antibiotic Susceptibility Pattern and Distribution of coa Genes in Coagulase-negative S. aureus from Ahvaz, Iran

BACKGROUND

Staphylococcus aureus is one of the important causes of clinical infections that can be more destructive by its antibiotic resistant strains.

OBJECTIVE

This study aimed to determine the antibiotic susceptibility pattern and distribution of mecA and coa genes in clinical isolates of S. aureus.

METHODS

Two hundred seventy-three specimens suspected to S. aureus were taken from hospitals of Ahvaz, southwest of Iran. Isolates were identified by standard microbiologic tests and confirmed by the molecular method. Antimicrobial susceptibility testing was carried out by disk diffusion method. The presence of mecA and coa genes was determined by PCR method.

RESULTS

Of a total of 200 isolates which were tested for coagulase tube test, 143 (71.5%) showed coagulase positive, and 57 (28.5%) showed a coagulase-negative reaction. Antibacterial susceptibility pattern of 200 S. aureus isolates showed the highest and lowest susceptibility rate to linezolid (98%) and ciprofloxacin (42%), respectively. The prevalence of methicillin-resistant S. aureus (MRSA) by detection of mecA gene was estimated as 47.5 % (95/200), of which the rate of MRSA in coagulase positive and negative isolates was 35% (50/143), and 65% (45/57), respectively. Meanwhile, coa gene was detected in 100% of coagulase positive and 28.1% of coagulasenegative isolates.

CONCLUSION

The results of this study showed that the number of atypical CNSA in our area is high. Since the coagulase test is an essential test for diagnosis of S. aureus, our findings regarding the emergence of CNSA are a warning about the misdiagnosis and selection of appropriate treatment approach for S. aureus isolates.

Antibiotic Resistance Patterns and Virulence Determinants of Different SCCmec and Pulsotypes of Staphylococcus Aureus Isolated from a Major Hospital in Ilam, Iran

Aims & Objectives:

The aim of this study is to evaluate genetic relatedness, antibiotic resistance pattern, and virulence characteristics of different types of S. aureus isolated from air, surfaces, staff, and patients in a Public hospital in Ilam.

Methods & Materials:

A total of 88 of 140 staphylococci identified as S. aureus by conventional and molecular methods were used in this study. Isolate samples were obtained from surfaces, staff, patients, and hospital indoor air. The sampling from staff and surfaces was done through using swab and air by standard pump. Antimicrobial susceptibility testing and presence different resistant and virulence determinants was assessed. Isolates were then typed by pulsed-field gel electrophoresis (PFGE) and SCCmec typing methods.

Results:

Out of 88isolates, 36 of them (40.9%) were MRSA. Among MRSA isolates, the range of resistance to antibiotic was 0% in vancomycin to 83.3% in gentamycin. The most prevalent resistant genes among gentamicin resistant S. aureus were acc (6')/aph (2”)Ia and aph(3”)IIIa. The most common erythromycin resistant gene was ermC. Surprisingly, SCCmec types I (30.5%), II (25%)were highly distributed. PFGE analysis showed 33 different pulsotypes.

Conclusion:

This study confirms that different isolates of MSSA and MRSA circulate in Ilam which differ in antimicrobial susceptibility, content of resistance, and virulence determinants.

Methicillin-resistant Staphylococcus aureus (MRSA) in Iran: A systematic review and meta-analysis

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most prevalent pathogens causing healthcare-associated infections. Accurate and updated data describing the epidemiology of MRSA are crucial for the development of national policies to control MRSA infection in each country. This study aimed to estimate the prevalence of MRSA in different parts of Iran.

METHODS

Several databases, including MEDLINE, Embase, Web of Science and Scientific Information Database (http://www.sid.ir), were searched from 1 January 2000 to 31 March 2016 to identify studies addressing the frequency or prevalence of MRSA in Iran. Comprehensive Meta-Analysis software v.2.2 was used to analyse the data.

RESULTS

Of the 725 records identified from the databases, 31 studies fulfilled the eligibility criteria. The analyses showed that the frequency of MRSA infections was 43.0% (95% confidence interval 36.3-50.0%) among confirmed S. aureus isolates. Further stratified analyses indicated that the prevalence of MRSA was higher in studies performed after the year 2000.

CONCLUSIONS

Since a high rate of MRSA infections was seen in this analysis, regular surveillance of hospital-associated infections, monitoring of antibiotic sensitivity patterns, and formulation of definite antibiotic policy may facilitate more accurate action for the prevention and control of MRSA.

Distribution of SCCmec Elements and Presence of Panton-Valentine Leukocidin in Methicillin-Resistant Staphylococcusepidermidis Isolated from Clinical Samples in a University Hospital of Isfahan City, Iran

INTRODUCTION

Coagulase Negative Staphylococcus (CoNS) is considered as a major pathogen of nosocomial infections among immunosuppressed patients.

AIM

The aim of this study was to identify the types of Staphylococcal Cassette Chromosome mec (SCCmec) and Panton-Valentine Leukocidin (PVL) gene among clinical Methicillin-Resistant S. epidermidis (MRSE) isolates collected from Isfahan.

MATERIALS AND METHODS

This cross-sectional study was performed from March 2014 to January 2015 at a tertiary care hospital of Isfahan, Iran. Antimicrobial susceptibility tests of S. epidermidis isolates were performed by the disc diffusion method. All the strains were screened for methicillin resistance based on resistance to cefoxitin (30 μg) disc and presence of mecA gene. Determination of SCCmec typing and PVL toxin gene were performed by PCR method. For categorical variables different groups were compared using the Chi-square test or Fisher exact test. A p-value of <0.05 was considered significant for all statistical tests.

RESULTS

The frequency of MRSE was 53.8% according to the presence of mecA gene. The overall resistance rate was high with ciprofloxacin (81.4%). PCR analysis showed that 17% (12/70) of MRSE isolate carried the PVL gene and 43% (30/70) were SCCmec type I; 11.4% (8/70) were type II; and 34.2% (24/70) were type IV, whereas, 11.4% (8/70) of the MRSE isolates could not be typed.

CONCLUSION

SCCmec type I was the major type of SCCmec, which indicates an emergence of this SCCmec type in the studied medical centers. Increased prevalence of SCCmec types in community is cause of an increase in antibiotic resistance among microorganisms.

Frequency of Aminoglycoside-Resistance Genes in Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Hospitalized Patients

Background

Staphylococcus aureus is one of the most important causative agents in community- and hospital-acquired infections. Aminoglycosides are powerful bactericidal drugs that are often used in combination with beta-lactams or glycopeptides to treat staphylococcal infections.

Objectives

The main objective of the present study was to determine the prevalence of aminoglycoside resistance among methicillin-resistant Staphylococcus aureus (MRSA) isolates in hospitalized patients in Sari and Tehran, Iran.

Methods

In this study, 174 MRSA strains isolated from different clinical samples, such as blood, sputum, tracheal exudates, bronchus, pleura, urine, wounds, and catheters, were collected from hospitalized patients in Tehran and Sari during 2014. Antibiotic susceptibility testing was performed against nine antibiotics with the Kirby-Bauer disk diffusion method according to CLSI guidelines. The MRSA strains were examined with oxacillin and cefoxitin disks. MRSA was then validated by detection of the mecA gene. PCR was used to evaluate the prevalence of the aminoglycoside-resistance genes aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’) among the MRSA isolates.

Results

The results of drug susceptibility testing showed that the highest rate of resistance was against erythromycin in Tehran (84.4%) and gentamicin (71.7%) in Sari. All isolates were sensitive to vancomycin, and all strains harbored the mecA gene. The aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’)-Ia genes were detected among 134 (77%), 119 (68.4%), and 122 (70.1%) of the isolates, respectively.

Conclusions

The present study showed a high prevalence of aminoglycoside-resistance genes among MRSA isolates in two cities in Iran.